Tumor suppressor
Think of tumor suppressors as the brakes that prevent cancer development and oncogenes as the gas pedal that accelerates cancer development. BRCA1/2 are tumor suppressors, along with many other examples such as P53, PTEN, RB, APC, and others.
There are several functions of tumor suppressor genes, such as ensuring the cell cycle controls and checkpoints, repairing DNA damage, promoting apoptosis, and preventing epithelial to mesenchymal transitions (EMT). The deactivation of tumor suppressor gene may lead to the formation of tumor.