The Cell Cycle & Mitosis Tutorial

Problem 9: Cancer

The sputum (fluid coughed up from the lungs) of many smokers contain cells with mutations (errors) in the genes for p53. The smoking induced mutations appear to be an early signal showing that cancer of the lungs will follow. What is the likely relationship between early p53 mutation and the development of lung cancer?

D.	p53 causes a cell to enter G0, blocking cell division.
	Incorrect. p53 only blocks the cell cycle until a cell can repair its DNA. Then the cycle continues unless the damage has included production of cancer causing genes. In this case, p53 in some unknown way stimulates apoptosis.