TACSTD2 and digestive system neoplasm: Overexpression of TROP2/TACSTD2 has been shown to confer a poor prognosis, notably among patients with gynecologic or gastrointestinal tumors.3 Its physiologic functions may be subverted to aid in proliferation and metastasis of tumor cells through various pathways such as insulin-like growth factor-1 (IGF-1) and extracellular regulated kinase-1/2 (ERK1/2).1 TROP2/TACSTD2 has also been shown to have some impact on the tumor immune microenvironment and may modulate immunotherapy response.