F. TOXICITY RESULTING FROM DYSREPAIR 3) Carcinogenesis ; a) Failure of DNA Repair: Mutation, the Initiating Event in Carcinogenesis 1 The products of protooncogenes include:

. (1) growth factors; (2) growth factor receptors; (3) intracellular signal transducers such as G proteins, protein kinases, cyclins, and cyclindependent protein kinases; and (4) nuclear (transcription factor) TFs