Henrietta Lacks, better known as HeLa to scientists around the world, is an African-American woman who unknowingly changed the course of medicine and science. On February 5, 1951, Dr. Howard Jones of Johns Hopkins Hospital diagnosed Henrietta with cervical cancer. A few days later, on February 8, 1951, Henrietta underwent her first radiation treatment for cervical cancer. Doctors, without Henrietta's permission, took two samples from her cervix: one from the tumor and one from healthy cervical tissue. These samples were given to Dr. George Otto Gey, head of tissue culture research at Johns Hopkins, who grew them into an immortal line of HeLa cells. HeLa cells have been instrumental in all types of research, such as developing the polio vaccine, studying the effects of radiation, and testing the safety of pharmaceutical products. In 2013, the genome of the HeLa cell was sequenced. The sequencing of HeLa cells has raised ethical concerns from the scientific community, but has also led to new discoveries, such as why Henrietta Lack's cancer was so aggressive and why the HeLa cell is an immortal cell line. The publication of the HeLa cell genome sparked outrage in the scientific community, as the Lacks family was not informed prior to publication. They had no idea that Henrietta's genome had been sequenced and was about to be published for the general public to see. The genomes of family members are similar, so if Henrietta's genome was publicly visible, so would the Lacks family's genome. People around the world would then learn private information about the Lacks family, such as whether they are predisposed to having high blood pressure or breast cancer. After Lac… halfway through the article… 7 genes were expressed at a higher rate in HeLa cells than in any human tissue (Landry et al. 2013). Many of these genes were linked to functions such as proliferation, transcription and DNA repair, which, if expressed at a high level, would allow the cells to reproduce so quickly and accurately that the lineage would be immortal. Immortality is the main feature that allowed HeLa cells to become famous, because they were the only sample of cells that Gey was able to culture. Henrietta Lack's cells changed the course of medical research around the world. They have been a crucial part of many medical discoveries and have also led us to think critically about the ethics of medical research. Although several immortal cell lines now exist, HeLa cells will remain one of the most widely used and influential cell lines in history.