Early this year, in The Immortal Life of Henrietta Lacks (Crown), Rebecca Skloot introduced readers to an intriguing combination of science and biography. The book got rave reviews and immediately hit best-seller lists. And Oprah Winfrey is turning it into an HBO movie.

In 1951, when 30-year-old Lacks was dying of cervical cancer, doctors took a sample from the tumor (without consent or financial compensation). What they discovered altered science forever: a line of cells that could live—and multiply like crazy—in a lab, allowing scientists to test on human cells outside the body. The result? Among other advances, the cure for polio and a breakthrough in AIDS research. In the 1980s, Richard Axel, MD, worked with HIV and what are now called HeLa cells (named after Lacks) and determined how HIV infects cells.

This provided a key step toward understanding—and maybe someday stopping—this complex virus.

Next time you swallow your HIV meds, remember Lacks, a Southern, African-American tobacco farmer and the mother of five children. In many ways, she's also the mother of modern microbiology cell culture.