ERBB2 and breast cancer: To provide a thorough characterization of the molecular alterations in BC as function of molecular subtypes (HR+, HER2+, HER2+HR+, and TNBC), tumor grade (GIII vs GI–II), patients age at presentation (young (≤40) vs old (>40)), and ethnicity (MENA vs non-MENA), a total of 96 well-characterized BC samples were subjected to total RNA profiling.