Oncogenes are mutated forms of normal genes (proto-oncogenes) that drive uncontrolled cell proliferation, contributing to cancer. Examples include the HER2 gene in breast cancer and the RAS gene in various cancers.
Tumor suppressor genes, on the other hand, act as the brakes on cell division. When these genes are mutated or inactivated, cells can grow uncontrollably. Key examples include p53 and BRCA1/2 genes.
