Noble laureates in Medicine, designed by Hannu Järviö, engraved by Slania and issued by Sweden on March 20, 2003:
Santiago Ramon y Cajal (1852 – 1934), a Spanish neuroscientist, pathologist, and histologist specializing in neuroanatomy and the central nervous system. His original investigations of the microscopic structure of the brain made him a pioneer of modern neuroscience. He received, together with Camillo Golgi, the Nobel Prize in Physiology or Medicine in 1906:

Severo Ochoa de Albornoz (1905 – 1993) was a Spanish physician and biochemist, and joint winner of the 1959 Nobel Prize in Physiology and Medicine with Arthur Kornberg for their discovery of mechanisms in the biological synthesis of RNA and DNA:

Issued as se-tennant:

This set was jointly issued with Spain. Slania engraved the Spanish stamps, but his name doesn't appear on them:

