 Thank you very much for that kind of introduction. It's a really great honor for me to be here tonight and to talk about fighting leukemia. When I first started my PhD project, I was really optimistic. I was working on the genetic basis of the resistance of leukemia. And with my father, I was thinking, we're going to be able to cure this deathly disease if we just need more and more information. However, when I progressed with my PhD project, I realized things weren't that easy. During that time, I came across a new suite similar to this one by the DKMS, which is a German registry for stem cell donors, and they were looking for a suitable donor for a patient with leukemia. And since I was working in the field, I was honestly a little bit ashamed because I thought I shouldn't register earlier. So I thought I'm probably not going to be able to save the whole world with my PhD project, but maybe there's one patient with leukemia who benefit from my stem cells. So I signed up. And tonight, I would like to give you a basic information about leukemia and also why stem cell transportation is for some of these patients the only chance for a cure. Leukemia is cancer of all bad cells. Every hour there's a new diagnosis here just alone in Germany, summing up to about 14,000 new cases each year. Compared to other cancers like breast cancer or lung cancer, leukemia is right where making only about 4% of all cancer diagnosis. In children, however, it's the most frequent type of cancer. The word leukemia originates from the Greek language, meaning white blood. The disease was first described in the 19th century. By then, the doctors didn't really know what it was. They only observed that in the blood of leukemia patients, they have this axis of white cells compared to the blood of a healthy individual. They even thought it might be an infection because by that time they didn't really know much about our blood cells. So in order to understand leukemia, we first have to get an overview about how our blood cells are generated. So this is a very simplified illustration of the different blood cells that are existing in our body. It could have been a very important purpose as far as they help. So for example, we have new cells that fight diseases like bacteria or viruses, and you've probably all heard about red-deaf cells that are important for transportation of oxygen. Importantly, even though all these cells look different, they have different sizes, different shapes, they look for different jobs in our body, they all originate from the same blood stem cells. These blood stem cells live in our bone marrow, and they have a, because, set up a new capacity, which means when they start dividing them for a new stem cell, but also a progenitor cell who's already a little bit more connected to becoming a mature stem dead, a mature blood cell. So the whole maturation process happens in the bone marrow and once the cell is ready, it would leave the bone marrow and migrate to the bloodstream. In leukemia, the stem cells of the progenitor cells become abnormal. They start to multiply in the bone marrow and accumulate there. Patients with leukemia don't necessarily die of the cancer cells itself, but these cells are not any longer able to produce the mature cells that live far out of their own health. So this slide summarizes what the doctors back in the 19th century didn't know, that leukemia is a stem cell disorder leading to an accumulation of leukemia glass, this is the white mass that we saw in the Black's temple, and that the patients that suffer from leukemia were like the mature blood cells. So in the next slides I would like to talk about how leukemias treat it. Like other cancers, the standard therapy for leukemia involves chemotherapy. However, there's one big challenge. So leukemias is a disease that doesn't just happen overnight, it's a long progress. It starts with healthy stem cells that acquire genutations as indicated here by these dots. Genutations are the cause that are caused by the damages to our DNA, for example by toxic chemicals or radiation. So over the years the stem cells will acquire more and more of these genutations, and eventually when the patient is diagnosed with pulmonary leukemia, we have a genetically diverse disease. When the patient is now treated with chemotherapy, this may lead to resistance of some of these cells, because they have acquired genutations that make them less sensitive to the chemotherapy. If a patient over all responds to the treatment, he's in a state that we call remission, so the healthy stem cells take over again. But unfortunately, as you can see here, in many times residual leukemia cells are still present in the patient. And over time, these cells start curming again, and the patient suffers from relapse, which is the recurrence of the disease. And unfortunately at this point, the patients who really don't respond to the chemotherapy any longer, and most patients who suffer from relapse will eventually die. So applying chemotherapy to a patient is always a matter of balance. On the one side, it won't be as hard as possible to cure leukemia cells. However, if you're too toxic, it will also affect the healthy and remaining stem cells that are left. So doctors came up with a different approach, and this is illustrated here in this slide. In the setting of a stem cell transplantation, the patient will receive a really harsh chemotherapy treatment, and usually this is combined with radiation. The goal of this really harsh treatment is, as indicated here by this cross, to really get rid of as many cells in the bone marrow as possible. And after this harsh treatment, the patient receives donor stem cells from a healthy individual. Over time, these stem cells will repopulate the bone marrow and start to regenerate all the mature blood cells that we have talked about. There's one big problem with this approach. You've probably heard about immune reactions when the patient receives a kidney or a lung transplant. In the setting of a stem cell transplantation, we are actually transplanting the immune system of a donor into the leukemia patient. So the immune cells will realize they're in a foreign environment and actually start to attack the body of the patient. So when we choose a donor for a leukemia patient, we have to make sure that this immune reaction is very little. But how can we predict that? The immune cells are recognized in foreign cells by cell surface markers. So if the cell surface markers of the donor and the recipient are pretty similar, the immune reaction will be little. And the type and the shape of these cell surface markers are encoded in our DNA. So when we're choosing a right donor, we have to perform genetic analysis. We are characterizing what is so-called the A to A type. Therefore, we look at five different genetic markers. For each of these markers, we have two versions, one that we have from our mother and the other one that we have from our father. But unfortunately, due to our genetic priority, there are not just two versions of these genes. In the whole human population, we have hundreds of different versions of these genetic markers. So just looking at these five genetic markers, we have 10,000 of possible combinations. It makes this unique, however, it also makes it also hard to find a donor that is genetically similar to us or to the immune patient. So the search for a suitable donor is usually the start of a new family because family members are genetically similar. A perfect match would mean that the two versions were all of the five markers that we're looking at are identical. Our mother or our father will never be a perfect match because we get 50% of the genetic information from each of them. But then when we look at siblings, since they usually share the same genetic pool, there's a 25% chance for every of our brothers or sister to be a perfect match. So the more siblings you have, the greater our chance is to find a suitable donor. So that's the reason why it should always be nice to your siblings, right? Because eventually they can save your life. When you look at other family members such as cousins, the chances are very little actually to find a perfect match. Overall, only about 30% of leukemia patients will find a matching donor in the family. So the majority of them depends on an unrelated donor. But how can we find that, especially when you think of the genetic priority? It's really like searching for a needle in the knee step. So international registries have been set up to facilitate the search to find a suitable donor, and that's what I'm going to be talking about in the next couple of days. BMS is one of the German registries for stem cell donors. It was founded in the 90s, and so far they have collected or they have registered about 9 million. Still about 10% of leukemia patients won't find a matching donor. So if you're willing to make an update on a leukemia patient, I would like to show you now how you can sign up. First of all, it's very easy and appropriate. All you have to do is you go online, you check if you're qualified, and you provide your contact information. A couple of days later, you will receive a bucket swap. Basically it looks like a Q-tip, and you rub that in the inside of your mouth. That collects enough cells, and you will send that back to the laboratory. They will perform genetic analyses and determine your age later. This information is stored anonymously in a global patient's search. So you could not only save someone here in Germany, but basically all over the world. In case you are a match for someone in their database, which actually only happens in 5% of the cases, the DKMS will get back in touch with you and check if you're still willing and also physically able to become a donor. And then there are basically two ways of how the stem cells are collected. In the majority of the cases, the so-called purple stem cell collection is performed. The stem cells that are living in our bone are triggered by a chemical to move outside into the purple bloodstream. And then from there on, as shown here in this picture, it is a machine who can basically filter out the stem cells from your blood. This whole procedure takes about 3-5 hours, and you see this guy smiling, it doesn't really hurt. And you can no warmer afterwards. In about 20% of the cases, a bone collection has to be performed. Some people think you have to get a donor from this vine, but it's actually a pelvic bone just close to your hips. It's done on a full anesthesia, and the doctors will take it even to collect about 5% of your total bone. So after a couple of weeks, your body has recovered the stem cells that you have lost. The DKS actually did a survey and asked past donors if they would do it again. And actually 95% of them said if they had a chance to donate again for a patient, they would do it. So that just shows that the procedure itself really is not as harsh as it's been on my finger. So finally we have the stem cells. Here this is an infusion, or this is a bone marrow sample, and this is really transfused to the patient and I have the pathways. And then the stem cells just know to go back into the bone marrow and from there they start to repopulate all their blood cells. The whole process takes about 10 days, and then the patient usually is feeling better. Over all of them, the stem cell transplantation increases to survive no chance of a patient by 20 to 30%. Which may not seem much, but for leukemia patients who have a really high risk disease and great chances to have a relapse and eventually die of disease, this is really the only chance they get to survive. So to wrap it up, I hope I was able to give you an overview about our blood cells and how they are important for our well-being, such as they help us to fight bacteria and virus and they transport the oxygen of the well-being. Leukemia is a cancer of all blood stem cells. And for some leukemia patients, the only chance to survive this death of disease is a stem cell transplantation. I would like to point out again that the routine process to become a stem cell donor is very easy. It probably takes longer to order a pizza online, and the procedure itself is not very harsh. So I hope I was able to encourage you to go online because it's even an English version of this website, so you have no excuse if you don't speak German. And register, and yeah, actually, so statistically speaking, we have about 7 to 8 people in this audience who might be a match for leukemia patients. I think this is a brilliant idea that someone here could be saving someone. So yeah, thank you very much for your attention and I hope to take your questions. We always give you the chance after you stop to ask your questions, which is also a great thing about this event. So speakers don't run away, they stay here, they answer your questions, and they also stay for the break. So if you have any more, you can still talk to them afterwards. So is there anyone who wants to ask anything? We have volunteers running around on the microphone, so I think there are people in the back having questions. So the microphone will come to you. You have to go and answer them. I didn't hear your question, sorry. I will just repeat the question for the radio recording. The question was, if you have an identical twin, how big is the chance? So if it's really an identical twin, so it looks the same like you, you have the same genes because you started from the very same act that split during the process. So an identical twin would be, from looking at the immune reaction, the perfect donor because you could just transplant any organ and the who says would never recognize the other person because the genes are the same. But there's one problem. What I did talk about is the immune system of the donor would actually also help to fight the residual leukemia cells that are in the patient. So when you transplant the bone marrow from an identical twin, this effect is lost. And the chance is actually for a relapse of higher and faster residual leukemia cells don't get killed by the donor cells. That makes sense. Would you mind to throw the cube to the other person? Thank you. My question is about the residuals themselves. My question is about the residuals themselves. Because I'm aware that first we have to take certain drugs which increase the amount of stem cells in the bone marrow. So what about the side effects? Because it might, you know, increase the amplification of those cells and it might cause, or increase the risk of mutations and other side effects perhaps. So you read some of this drug treatment and then you can download your... So the side effects of the purple stem cell collection, right? So you're right. We're giving chemicals that will trigger your stem cells to move from the bone marrow to the bloodstream. And this has only been done for like a couple of 10 years. So the long term side effects are still unclear. But I think so far there's no data showing that there's really a long term negative effect. Don't necessarily feel some pain. That's probably because the cells are leaving the environment. But I'm not aware that there's really a bad side effect. My question is, do we know why leukemia is rare in adults but very common in children? Yes, so I repeat the question. Why leukemia is rare in adults and more common in children? I think it just has to do with the genetic basis of the disease. So it's a long, usually it's a long process to gather leukemia. And that's why cancer in general, if you think of skin cancer or other cancers, they just happen over and over again. And then there are some other cancers, and for example also leukemia in children that are already starting at a very early age. Sometimes we can even transcribe leukemia cells already at the bloodstream more maybe and leukemia cell happens a couple of years later. So it might just be my chance that actually these diseases happen over again and other cancers just take longer to develop. Thank you very much for your answer. Thank you for your questions. And no problem.