TACSTD2 and breast cancer: This was also shown in the gene expression analysis from the I-SPY 1 study (n = 149), with no association between the TACSTD2 gene expression and pathological response to chemotherapy in all BC subtypes.30 Furthermore, in the TROPiCS-02 study, no significant association between TROP2 IHC expression and response to anti-TROP2 therapy; ie, Sacituzumab Govitecan in HR+/HER2− BC.24 Altogether, this rejects the predictive role of membranous TROP2 protein expression to response to either chemotherapy [our study] or Sacituzumab Govitecan [TROPiCS-02 study].24