The signalling by EGFR-ErbB3 heterodimers may play an important role in colon cancer cell lines; in fact, inhibition of AKT phosphorylation and cell proliferation by the EGFR-specific inhibitor erlotinib (Tarceva) correlated with expression of ErbB3 [67]. The gene discussed is ERBB3; the disease is malignant colon neoplasm.