ERBB2 and breast carcinoma: Clinically significant classifications of the intrinsic, molecular subtypes of invasive breast carcinomas include luminal B-like HER2-positive, luminal B-like HER2-negative, and luminal A breast cancer, as well as triple-negative breast cancer (TNBC), HER2-enriched (nonluminal), and luminal B-like HER2-positive (Cheang et al., 2015; Nagini, 2017).