A cancer cell that makes and secretes the growth factor for which it has receptors can divide whenever it wants, and not wait around for some other tissue in the body to decide to synthesize the growth factor it needs. There are other requirements for growth besides growth factors that cancer cells need less of a. Cancer cells require less calcium to divide than normal cells. B. Proteases chew up the proteins on the cell's own surface. This makes the cell have abnormal bits of protein sticking out of its membrane surface instead of the complete normal proteins. Surface molecules on a cell determine how a cell interacts with surrounding cells, so if the normal molecules are damaged, the cell will not interact normally with other cells.
Cancer cells make abnormal molecules to put on their surface.
This includes abnormal proteins, carbohydrates and lipids. The membrane of a cell is made of lipid. Sticking out the the lipid surface are proteins that are floating around in the membrane and carbohydrates attached to either proteins or lipids. Length of cell cycle is shorter than normal 2. No contact inhibition of division 4.