Answer:
Proto-oncogenes may have mutated to become oncogenes in these cells
Explanation:
Cancer cells are characterized by key properties such as an abnormally rapid rate and poor differentiation. Proto-oncogenes are genes that lead normal cells to become cancer cells when they are mutated. Many proto-oncogenes are involved in the control and progression of the cell cycle, and apoptosis (programmed cell death) pathway. Some examples of protooncogenes include 1-the Ras gene, which is required for differentiation, growth, and cell survival (mutations of this gene have been reported in pancreatic cancer, lung cancer, colon cancer and thyroid cancer), 2-the Myc gene (mutated in Burkitt's lymphoma), 3- the Her2 receptor (a receptor kinase associated with breast cancer), etc.