Biochemistry of Cancer - Role of Proto-Oncogenes and Oncogenes 

Proto-oncogenes are normal genes that help cells grow. An oncogene is any gene that causes cancer. ... Because proto-oncogenes are involved in the process of cell growth, they can turn into oncogenes when a mutation (error) permanently activates the gene. This video documents the role of proto-oncogenes and oncogenes in cancer development.