"What’s more, the WI-38 strain has helped to generate billions of dollars for companies that produce vaccines based on the cells, yet it seems that the parents of the fetus have earned nothing. That recalls the earlier development of the HeLa cell line, named after the woman whose tumour gave rise to the cells and chronicled in Rebecca Skloot’s book The Immortal Life of Henrietta Lacks (Crown, 2010). As with HeLa, the WI-38 case highlights questions about if, and how, tissue donors should be compensated that are still urgently debated today. Last month, for example, some scientists in the United States found themselves barred from using new stem-cell lines derived from human embryos because women had been paid for the eggs used to make them (see Nature http://doi.org/mv2; 2013). The story of WI-38, unlike that of HeLa, also has its own controversial twist because it was derived from an aborted fetus. For 40 years, anti-abortion activists have protested against the use of WI-38 and vaccines developed from it. “It’s still a live issue,” says Alta Charo, a professor of law and bioethics at the University of Wisconsin Law School in Madison. “We still have people who refuse to take these vaccines because of their origins in fetal tissue."