Peter Medawar, Brazilian-English biologist and immunologist, Nobel Prize laureate (died 1987)

Sir Peter Brian Medawar was a British biologist and writer, whose works on graft rejection and the discovery of acquired immune tolerance have been fundamental to the medical practice of tissue and organ transplants. For his scientific works, he is regarded as the "father of transplantation". He is remembered for his wit both in person and in popular writings. Richard Dawkins referred to him as "the wittiest of all scientific writers"; Stephen Jay Gould as "the cleverest man I have ever known".

The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, according to Alfred Nobel's 1895 will, are awarded "to those who, during the preceding year, have conferred the greatest benefit to humankind". Nobel Prizes are awarded in the fields of Physics, Medicine or Physiology, Chemistry, Literature, and Peace.

February 28 is the 59th day of the year in the Gregorian calendar; 306 days remain until the end of the year.