Trop-2 is expressed in more than 90% of BC, especially triple-negative BC (TNBC).110 The ADC sacituzumab ­govitecan (SG) conjugates an anti-Trop-2 mAb with a topoisomerase I inhibitor, SN-38, an active metabolite of irinotecan. This evidence concerns the gene TACSTD2 and breast cancer.