By localizing Trop-2 expression via IHC in 702 breast tumor samples from patients, Ambrogi et al., found that localization of Trop-2 in the membrane is an unfavorable prognostic factor for overall survival (HR 1.63; p = 0.04), whereas intracellular Trop-2 had a favorable impact on prognosis and disease relapse (HR 0.48; p = 0.003) [29]. Here, TACSTD2 is linked to breast neoplasm.