<unk>  is the process of malignant transformation leading to the formation of a tumor (tumorigenesis). It is characterized by a progression of changes on cellular and genetic level that ultimately reprogram a cell to undergo uncontrolled cell division, thus forming a malignant mass.
Oncovirinae, retroviruses which contain an onc gene, are categorized as oncogenic because they trigger the growth of tumorous tissues in the host. This process is also referred to as viral transformation.
carcinogen a substance, radionuclide or radiation directly involved in the promotion of cancer.
mutagen a physical or chemical agent that changes the genetic information of an organism.
teratogen
oncogene a modified gene believed to cause cancer.
Oncogenesis
Carcinogenesis
Neoplasia
Virilization
Growth inhibition
Wasting
Hyperplasia
Tumor