 So for protein structure, we're going to use the genetic code. What's the advantage of this? Well, it has to do with those silent mutations. If I'm interested in understanding protein structure and how conserved protein structure is, the amino acid sequence is going to be more conserved than the DNA sequence, precisely because I don't have to worry about the silent mutations. So I have to confess that in 99% of everything I do, we work with amino acid sequences. That means that we move on from those long DNA sequences and typically represent something like this. It's also a fact of three fewer letters, which is kind of nice. And again, every letter corresponds to a single amino acid. You can probably imagine why we went on from the three letter code to the one letter code given the amount of sequence information we have today. What can we do with this? Well, the problem is that I have a lot of this information today. Remember what I said about GenBank. One thing I've realized, these numbers are not meaningful to you. They're impressive to me because I know how they developed. So you know what I did? I picked out an old slide that I had in a different class roughly 10 years ago and then just modified the format.