These cells from one fetus have saved the lives of millions of people.

One of the first and eventually most widely available fetal stem cell strains, WI-38 was harvested and has arguably helped save more lives in the ensuing years than any other created by researchers.

http://www.metafilter.com/129490/These-cells-from-one-fetus-have-saved-the-lives-of-millions-of-people