Marshall Nirenberg 1927–2010

of the true giants in the history of science. Marshall Nirenberg, the man who deciphered the genetic code, was taken from us by a rare neuroendocrine cancer. He was 82 years old. I was one of the many scientists who had the good fortune to be trained in Marshall's lab, to be exposed to his brilliance , to be instilled with his values, and to be inspired by his enthusiasm for the discovery of important new truths in science. An incredible cornucopia of scientists were trained and profoundly influenced by him: and many others. What drew us to him? What did we learn from him? What is his ultimate legacy to mankind? I met Marshall for the first time in July 1966, when I interviewed for a fellowship in the National Heart Institute. I had followed his work during my medical training and was in awe of his discoveries. With great trepidation, I sat down and began to chat with him about his work on the genetic code and the work he was now doing. He put me at ease immediately. Marshall had no pretense. He had no need for pretense. His self-confidence, based upon accomplishment, and his self-effac-ing persona drew me in as we talked for over an hour. As we discussed the potential for my joining his lab, I asked him a question that I had been grappling with for some time: How did he handle the intense competitive environment surrounding the work on the genetic code? He smiled and said, " Ed, science is hard work. 99% of what you try fails. If you go into science, work on something that really matters. So if you discover something, it will be important. " I agreed to join his lab. It was the pivotal decision in my scientific career. The world of science knows the substance of his work: He opened up the mystery of the genetic code with the poly-U-polyphenylalanine experiment, then with the triplet binding assay with Phil Leder, and finally with the triplet termination assay with Tom Caskey. From UUU to all 64 triplets: the " periodic table " for molecular biology. But how many have read the poly-U paper—I mean, really read it? Marshall's approach to science comes through, loud and clear. Every possible control is tested. Every method is described so that anyone else can reproduce it. Every piece of data, even imperfect …