Although Trop‐2 gene expression was detectable in all breast cancer subtypes, it was lower in HER2+ compared to HR+/HER2‐ and TNBC tumors and, interestingly, grade I tumors showed increased expression, possibly paralleling with our finding of accrued Trop‐2 in T1 tumor stage. Here, TACSTD2 is linked to breast carcinoma.