EGFR and lung cancer: Mouse lung cancer models that express the EGFR mutations Del19-T790M or L858R-T790M, each with concurrent cMET overexpression, showed no significant tumor regression in response to monotherapy that targeted EGFR or cMET alone.21 By contrast, combination therapies that simultaneously targeted EGFR and cMET were highly efficacious against EGFR-TKI-resistant tumors codriven by Del19-T790M or L858R-T790M and cMET.