With all this talk about stem cells and whether it’s, in President Obama’s words, “dangerous and profoundly wrong” to research human cloning, I can’t help but think of the HeLa cell line that has played such a vital role in everything from eradicating polio to to early space shuttle missions.

And talk about profoundly wrong — the cells’ owner was never told that her tissue was going to a medical center at Johns Hopkins for special analysis, much less the role she would unwittingly play in the future of medicine.

Her name was Henrietta Lacks, a 31-year-old black mother of five in 1950s Baltimore, Md. When she went in for a routine biopsy, the doctors discovered a tumor with most unusual cell activity: they were essentially immortal. Normally, cellular samples have a limited shelf life in a laboratory. They’ll only divide a certain number of times before the chromosomes reach their Hayflick limit.