CYCS and breast cancer: Bcl2 is a major anti-apoptotic protein located at position 18q21.33 that encodes the Bcl2 protein, which is an integral outer mitochondrial membrane protein that prevents programmed death of different cells including cancer cells and inhibits the release of cytochrome C. The expression of the Bcl-2 proteins are mainly associated with incidence and progression of breast cancer [40].