ERBB2 and breast cancer: Treatment options for HER2 BC patients have increased steadily in recent years, and with a myriad of novel approaches under preclinical investigation or clinical validation (Figure 2), it is expected that in a few years, the conventional anti-HER2 antibodies and TKIs will be replaced by more effective and innovative therapies (ADCs, bispecific antibodies, CAR-T cells, nanotherapy, and immunotherapy).