SLC39A6 and breast cancer: LIV-1 is a transmembrane protein with metalloproteinase activity, belonging to a subfamily of ZIP (IRT-like proteins) zinc transporters with heterogenous expression across different normal tissues with high expression in both HR+ breast cancer and TNBC.89 Ladiratuzumab vedotin (LV) is an ADC with a humanized monoclonal antibody targeting LIV-1 by a cleavable linker to a cytotoxic payload, monomethyl auristatin E with antitubulin effects.