ADCs have shown strong antitumor activity in solid tumors, especially breast cancer.27 For breast cancer, anti-HER2 ADCs and anti-Trop-2 ADCs are promising.4,13 In our multi-omic data from a TNBC patient cohort (n = 360),18 we observed that the expression of ERBB2 (encoding HER2 protein) was higher in the LAR subtype than in other subtypes, both at the protein (P < 0.001, Fig. 5a) and mRNA levels (P < 0.001, Fig. 5b), suggesting that patients diagnosed with the TNBC LAR subtype might benefit from anti-HER2 ADCs. Here, TACSTD2 is linked to breast cancer.