Oncogenes are genes that cause cancer when mutated and apoptosis is programmed cell death.

The genes that code for the positive cell cycle regulators are called proto-oncogenes. Proto-oncogenes are normal genes that, when mutated in specific ways, become oncogenes: genes that contribute to a cell to becoming cancerous. There are many ways for this to happen. For example, a mutation can cause a change in the function, location, expression, or activation of a protein.

If the cell cannot reproduce with the oncogene mutation, it will not propagate to future daughter cells. However, if the mutation can be passed on, subsequent daughter cells may acquire even more mutations that will be increasingly detrimental.

Apoptosis is programmed cell death, a normal process that destroys cells no longer needed by the body. Apoptosis allows a cell to die in a controlled manner that prevents the release of potentially damaging molecules from inside the cell and allows cellular material to be recycled. Many checkpoints monitor a cell’s health, and if abnormalities are observed, a cell can initiate the process of apoptosis. However, in some cases, such as a viral infection or uncontrolled cell division due to cancer, the cell’s normal checks and balances fail. External signalling can also initiate apoptosis.