Cancer

Although each cell in the body maintains itself and carries out its specific function, it is part of a large colony of collaborating cells that constitute the whole organism. A cell communicates with its surrounding cells by releasing chemical messages, in a process called signal transduction. These Multiple systems interact to control the cell cycle, ensuring that cell division occurs only when it is advantageous for the organism and when undamaged DNA is availale for replication. Cancer may occur when any one of these systems is disrupted. messages bind to specific receptor proteins on the surface of the surrounding cells. The gene expression of these cells is changed as a result of the messages.

A hyperplastic cell or a cancerous cell will stimulate neighboring cells to grow by secreting growth factors. Several types of genes can be mutated in tumor cells: oncogenes, tumor suppressor genes, DNA repair genes, and genes involved in cell mortality.