ERBB2 and cancer: Characterized by the molecular subtypes, we found MCT-1 induction in 93.8% of ER+/PR+/HER2+ cancers (n = 16), 100% of ER−/PR−/HER2+ (n = 8) cancers and 70.8% of TNBC (ER−/PR−/HER2−) (n = 113).