Tumor-associated calcium signal transducer 2(Tacstd2), also known as Cell surface glycoprotein Trop-2, belongs to the EPCAM family. Tacstd2 expressed in kidney, lung, ovary and testis and has high levels of expression in immortalized keratinocytes. Tacstd2 may functions as a growth factor receptor. It has negative regulation of branching involved in ureteric bud morphogenesis, cell motility, epithelial cell migration, ruffle assembly, stress fiber assembly and substrate adhesion-dependent cell spreading. Also, it has positive regulation of stem cell proliferation. Tacstd2 is capable of transducing an intracellular calcium signal and may play a role in tumor growth. It also has adhesive functions.