ERBB2 and cancer: Conventional ADCs targeting transmembrane proteins, such as human epidermal growth factor receptor 2 (HER2), MET, nectin cell adhesion molecule 4 (NECTIN4) and trophoblast cell surface antigen 2 (TROP2) (Figure 2), have been approved for the treatment of specific cancer types by the US Food and Drug Administration (FDA) and regulatory agencies in other countries (Colombo et al., 2024; Dumontet et al., 2023; FDA, 2025; Maecker et al., 2023).