 Checkpoint inhibitor drugs, such as anti-PD1 slash PDL1, are a new type of cancer treatment that has shown great promise in treating certain types of cancer. These drugs work by blocking the interactions between two proteins, PD1 and PDL1, on the surface of cells. This blocks the signals that tell the immune system not to attack the cancer cells, allowing the immune system to recognize and fight them. Although these drugs have had some success in treating certain types of cancer, they are only effective against certain types of cancer and their effectiveness varies from patient to patient. Additionally, there are still many questions about how best to use these drugs, including whether or not they should be used alone or in combination with other treatments. This article was authored by Hashim al-Alsab, Hashim al-Alsab, Samrash Sao, and others.