in view of the well known role of many factors in carcinogenesis the concept of carcinogenesis as a multistep process as well as the concept of cocarcinogenesis and the role of cofactors other than viruses , such as radiation and chemicals , aging , hormones , graft vs host reaction , environmental factors etc. , will have to be carefully considered .
C0596263
carcinogenesis
C0009181
cocarcinogenesis