Scientist.
Ilya Ilyich Mechnikov (15 May [O.S. 3 May] 1845 – 15 July 1916) was a Russian biologist, zoologist and protozoologist, best remembered for his pioneering research into the immune system. Mechnikov received the Nobel Prize in Medicine in 1908, shared with Paul Ehrlich, for his work on phagocytosis. He is also credited by some sources with coining the term gerontology in 1903, for the emerging study of aging and longevity.
Source:
1.) "There is no clear record that he was professionally restricted in Russia because of his lineage, but he sympathized with the problem his Jewish colleagues suffered owing to Russian anti-Semitism; his personal religious commitment was to atheism, although he received strict Christian religious training at home." Alfred I. Tauber, Leon Chernyak, Metchnikoff and the origins of immunology: from metaphor to theory, page 5.