ERBB2 and breast cancer: Next, we further investigated for an association between TMI and known prognostic molecular phenotypes in breast cancers (Luminal A/B, HER2+ and basal subtypes).12,13 Our prognostic TMI was highest among the most adverse molecular phenotypes (basal and HER2+ tumors), which were known to harbor the worst prognosis (Fig. 3b and Supplementary Data file S10).