Overall, we have here provided the proof of concept of the therapeutic valence of a novel scDb-hERG1-β1-TRAIL antibody, which targets the hERG1/β1 integrin complex as well as TRAIL-Rs in breast cancer and TNBC which overexpress the complex, hence representing a novel antibody–drug conjugate for difficult-to-treat cancers. This evidence concerns the gene KCNH2 and cancer.