ERBB2 and breast cancer: Enhertu, a highly successful ADC in clinical practice, is currently used to treat various oncological indications, including HER2-positive breast cancer, non-small cell lung cancer, and gastric or gastroesophageal junction adenocarcinoma, all of which have shown promising therapeutic efficacy (Narayan et al., 2021; Balamkundu and Liu, 2023).