Longtime readers may remember that my early longevity research centered on antioxidant synergism and selenium. In 1959, I was researching the possible role of selenium as “Factor 3” proposed by Drs. Klaus Swartz and Calvin Foltz in 1958, when I discovered a synergistic role of selenium and vitamin C. At that time, selenium was not known to be an essential nutrient for humans or other animals. In 1973, Rotruck and colleagues discovered that selenium was a component of an essential enzyme (1) and, in 1989, it was discovered that selenium forms the active site in the amino acid selenocysteine (2), which is now known to be the 21st amino acid specified by our genetic code. In fact, unraveling the mysteries of selenium biochemistry has altered our understanding of the genetic code. We now know that there are at least 20 active biochemicals made in humans that contain selenocysteine as their active site, but we still don’t know many of their functions.