Subsequent studies confirmed a developmental role for Trop2 during embryogenesis [7], yet the protein’s best-documented function is its pervasive overexpression in a broad spectrum of solid epithelial malignancies including oral, head-and-neck, thyroid, lung, esophageal, gastric, colorectal, pancreatic, breast, renal, uterine, cervical, and ovarian carcinomas, as well as gliomas and several sarcoma subtypes [8,9,10]. This evidence concerns the gene TACSTD2 and sarcoma.