Bloody unfair: Jan Janský, a Czech serologist, neurologist, and psychiatrist, is credited with discovering the first classification of blood into the A, B, AB, and O blood types, which laid the foundation for the ABO blood group system. Despite his major contribution to medicine, he did not receive the Nobel Prize for his work. In 1917, an American medical commission recognized Janský's classification over that of Karl Landsteiner, who won the Nobel Prize in Physiology or Medicine in 1930 for a similar discovery. Janský's classification system remains in use today.