CCND1 and breast cancer: Other oncogenes that are frequently amplified in breast cancer include C-MYC, FGFR1 and CCND1. C-MYC, located at 8q24, encodes a transcription factor with a basic region/helix-loop-helix/leucine zipper domain, which is a key regulator of cell growth, proliferation, metabolism, differentiation, and apoptosis [8].