From a panel of 12 metastatic murine mammary tumor cell lines (4T1, 6DT1, D2A1, E0771, EMT6, F311, HRM-1, M6, Met-1, MVT1, r3T, and TS/A-E1), commonly mutated genes in human breast cancers were found to be present, including PIK3CA and TP53. In terms of CNV, only minor overlaps with the CNVs from human breast cancers were noted and were complemented with transcriptomic clusters. The gene discussed is PIK3CA; the disease is breast cancer.