I have to give a 30 minute speech in a couple of weeks about a specific protein. The protein needs to have a crystal structure and have some type of societal impact. I would like a protein that is involved in sports or bodybuilding because that is the subject outside of school that I am most interested in. My question is basically what are the names of some well versed proteins that I can give my speech about (the protein could also have a role in heart disease, cancer, respiratory disease or diabetes as well) . If you can give me a few that would be great.

PS- The protein does NOT have to be involved in sports, its just a preference. It also cannot be insulin.