Furthermore, we recently demonstrated that PAQR8 is spontaneously upregulated and CN-gained in recurrent mouse mammary tumors that arise following therapy in a manner analogous to that observed in patients, promotes mammary tumor recurrence in mice, confers resistance to anti-estrogen therapy, anti-HER2 therapy, and chemotherapy, and is associated with poor overall survival as well as survival following recurrence in breast cancer patients [9]. This evidence concerns the gene ERBB2 and breast cancer.