ERBB2 and breast cancer: Targeted NGS showed that the most frequent genetic alterations observed in IBC samples are represented by TP53 (58%), HER2 (amplified in 53%), ATM (53%), APC (37%), and HER3 (26%); interestingly, APC, ATM, and HER3 alterations only occur at low frequencies in non-IBC breast cancers [162].