HeLa cells are a line of human cells derived from the cervical cancer patient Henrietta Lacks in 1951. These cells were the first immortal human cell line, meaning they can divide indefinitely in laboratory conditions. HeLa cells have been crucial in medical research, contributing to advancements in vaccines, cancer treatments, and understanding various diseases. The use of HeLa cells has raised ethical questions regarding consent and the use of human tissues in research. Henrietta Lacks did not give permission for her cells to be used, leading to discussions about patient rights and the importance of informed consent in medical research.