Fifty years ago, a microbiologist named Leonard Hayflick developed a strain of cells named WI-38 from the lungs of an aborted fetus. The strain of cells have been used to produce life-savings vaccines worldwide, but have also had a history riddled with controversy:

“The cells have played ‘a very critical role in studying cellular senescence,’ adds Rugang Zhang, who works in this field at the Wistar Institute. That’s because they so reliably stop replicating after about 50 divisions and because scientists have, over time, built up a wealth of knowledge about the reasons why. In the 1990s, for instance, WI-38 was used to discover the most widely used marker of cellular senescence10. More recently, Zhang’s team used the cells to discover a pathway by which the complex of DNA and proteins known as chromatin controls cell proliferation11.

“But the controversies surrounding the cells have rumbled on. Back in July 1973, Hayflick received a call at home from a senior medical officer at NASA. Skylab 3 had taken off several hours earlier from the Kennedy Space Center in Florida, bound for the Space Station. The NASA physician was contending with anti-abortion demonstrators who were protesting about the presence aboard of WI-38 cells, which were going to be used to detect the effects of zero-gravity on cell growth and structure. Once Hayflick explained that the abortion from which the cells were derived had occurred legally in Sweden, the physician said that he would defuse the situation — but concerns among anti-abortionists about WI-38 have lasted to this day.”