Given that mice bearing these tumors were still resistant to irinotecan administrations, it was hypothesized that by increasing the levels of Trop-2 in the tumor cells, a greater amount of SN-38 was delivered by SG resulting in pushing the cells past a DNA damage threshold that even its proficient HRR pathway was unable to overcome resulting in triggering apoptosis and cell death. This evidence concerns the gene TACSTD2 and neoplasm.