HeLa cells are a type of human cell line that was derived from the cervical cancer cells of Henrietta Lacks in 1951. These cells are unique because they can divide indefinitely in laboratory conditions, making them invaluable for scientific research. They were the first immortal human cell line and have contributed significantly to medical advancements. Researchers use HeLa cells to study various diseases, including cancer, and to test the effects of drugs. Their ability to replicate quickly allows scientists to conduct experiments efficiently. HeLa cells have played a crucial role in developing vaccines, including the polio vaccine, and in understanding cell biology.