EGFR and breast cancer: Basal-like tumors are characterized by the genomic expression of the "basal cluster," a cluster of genes, including the epidermal growth factor receptor (EGFR also called HER1), basal cytokeratins 5/6 and c-Kit.8,12-14 Compared with other breast cancer subtypes, cells in the basal-like tumors have a higher degree of genetic instability and also a greater rate of loss of heterozygosity.15