Cancer is a disease in which cells divide out of control, and with specific types of gene damage, the cell starts dividing out of control, forming a tumor. Given these facts, cancer and tumors are a result of specific types of: among the following options:
- organs
 - cigarettes
 - radiation
 - layers of fat
 - gene damage
 - rays or beams
 - Chemical energy
 - the skin


 

     gene damage    