I'm noticing a lot of research abstracts mentioning p53 lately. I don't have a clue what it is, but if you look through old posts at ThisIsMS, you'll see some threads from OddDuck and BioDocFL talking a bit about it. I also just saw this abstract from last year from Vanderbilt and one of the oft-referenced researchers around here, Sriram.
Defective ATM-p53-mediated apoptotic pathway in multiple sclerosis.
Ann Neurol. 2005 Oct;58(4):577-84.
Deng X, Ljunggren-Rose A, ...