The 2009 Nobel Prize in Medicine went to three American researchers whose work on the ends of DNA and the enzyme controlling them link the disparate subjects of cancer, aging and evolution.
Oh, and there's a dose of politics.
Elizabeth Blackburn and Jack Szostak were colleagues in the early 1980s, and Carol Greider was a Blackburn grad student, when Greider discovered the enzyme telemorase in 1984. Greider thus becomes famous for winning a science Nobel at the relatively "young" age of 48.
Blackburn and Greidner worked on how telemorase builds telomeres at the end of DNA, redundant genes that protect the underlying DNA structure like a plastic cap on a twisted electrical connection. Telemorase declines as we age, but becomes abundant in cancer.