These signals are interpreted in the nucleus, and the cell reproduces its genetic information and divides into two identical daughter cells through a process called mitosis. Cancer cells do not obey this rule and divide even when they do not receive the proper signal. In addition to the signal that normal cells receive that tells them to divide, they are also told when to stop dividing. This prevents the creation of too many cells. In reality, this process of cell division is a highly ordered process. This is a critical problem in cancer, because cancer cells do not obey or require normal signals to divide. This could lead to the formation of a mass of cells that accumulate and could form a tumor. Also different from nomadic cells is the ability of tumor cells to divide indefinitely. An important point about cells is that, regardless of their work in the body, they all have the same general structure and have different types of organelles that perform different important functions for the cell. Of particular importance to cancer is the organelle known as the nucleus. The core contains the blueprint of information for each of us, just as a manual would contain instructions for a chair. Specifically, this information is contained in the chromosomes that reside in the nucleus. The individual units of information are called genes. At the chemical level, genes are made up