ERBB4 and neoplasm: It has been discovered that the over-activation of the EGFR family of RTK, which includes EGFR (EGFR/HER-1 or ERBB-1), HER-2 (Neu or ERBB-2), HER-3 (ERBB-3), and HER-4 (ERBB-4), promotes the growth and progression of numerous tumor types.