Cancer cells and normal cells differ in many ways. One difference is that cancer cells are less specialized than normal cells, whereas normal cells mature into very distinct cell types with specific functions. This is one reason that, unlike normal cells, cancer cells continue to divide without stopping.

Cancer cells go through the checkpoints within the cell cycle without being checked correctly, like a normal cell is, and they begin to divide. If DNA is damaged and copied, and the cell doesn’t recognize this and splits, a cancer cell is formed due to the faulty DNA being left in the new cell. Cancer cells are also able to ignore signals that normally tell cells to stop dividing or that begin “programmed cell death”, or apoptosis, which the body uses to eliminate unneeded cells.

Cancer cells have the ability to influence normal cells, molecules, and blood vessels that surround and feed the tumor, ultimately increasing the growth rate of the tumor. Cancer cells are also often able to evade the immune system, a network of organs, tissues, and specialized cells that protect the body from infections and other conditions. Although the immune system normally removes damaged or abnormal cells from the body, some cancer cells are able to “hide” from the immune system.Tumors can also use the immune system to stay alive and grow. For example, with the help of certain immune system cells that normally prevent a runaway immune response, cancer cells can actually keep the immune system from killing cancer cells.