Cells are the basic building blocks of all living organisms; they have various structures like the nucleus, which contains genetic material, and organelles, which perform specific functions to keep the cell alive and functioning properly. Cancer occurs when cells begin to grow uncontrollably and divide without the normal regulatory mechanisms, often because of genetic mutations. Henrietta Lacks’ cells, known as HeLa cells, were different because they possessed the ability to divide indefinitely and thrive outside the human body, leading to significant advancements in medical research.