NECTIN4 and neoplasm: Because NECTIN4, CLDNs and classical CDHs are located at cell-cell junctions in polarized epithelial tumor cells but diffuse to nonjunctional locations in contact-naïve intermediate or mesenchymal tumor cells (Ebnet, 2017; Nakayama et al., 2024), human/humanized ADCs with cleavable linkers and cutting-edge payloads that target these adhesion molecules are expected to be active on aggressive and/or heterogenous solid tumors with a spectrum of epithelial–mesenchymal transitions in part through bystander killing effects.