Nearly all cancers are caused by abnormalities within the genetic material of the reworked cells. These abnormalities could also be owing to the consequences of carcinogens, like tobacco smoke, radiation, chemicals, or infectious agents. Different cancer-promoting genetic abnormalities could also be indiscriminately non heritable through errors in deoxyribonucleic acid replication, or square measure heritable, and therefore square measure gift all told cells from birth.