The human epidermal growth factor receptor (HER) family, which includes epidermal growth factor receptor (EGFR, HER1, erbB1), HER2 (erbB2, neu), HER3 (erbB3), and HER4 (erbB4), has been reported to be involved in the regulation of proliferation and differentiation in a variety of tumors, especially CRC (Sergina and Moasser 2007). The gene discussed is ERBB4; the disease is colorectal carcinoma.