ERBB2 and carcinoma: BRCA1 could be characterized as having a basal phenotype, ER-negative and HER2-negative, with up-regulation of cyclin A and caspase 3, but downregulation of cyclin D1 and D3, CDKIs (p16, p21, p27), and BCL2, the opposite phenotype from most BRCA2 carcinomas.