For sacituzumab govitecan to operate, an antibody targeting the most common kind of BC-specific antigen, a human trophoblast cell surface antigen 2 (Trop-2), must be combined with the enzyme inhibitor SN-38 (topoisomerase I inhibitor) through a unique hydrolyzable linker [19,20,21]. This evidence concerns the gene TACSTD2 and breast cancer.