Answer:
Proto oncogenes.
Explanation:
Proto oncogenes may be defined as the genes that play an important role in the cell functioning and its growth. The proto-oncgenes require enzymes and proteins that are normal for the other cells.
The main function of the proto oncogene is cell division. Any mutation or change in the proto oncogene results in the formation of oncogenes. These oncogenes are responsible for the formation of the cancer development in the individual.
Thus, the answer is proto oncogenes.