Copy number aberrations (CNAs) in known breast cancer driver genes (Curtis et al., 2012) present in the PDTXs included gains/amplifications of MYC (78%), CCNE1 (34%), ZNF703 (25%), CCND1 (31%), MDM2 (25%), and ERBB2 (9%) and deletions of PTEN (41%), PPP2R2A (72%), CDKN2A (47%), and CDKN2B (47%). This evidence concerns the gene MDM2 and breast cancer.