EGFR and cancer: Since >10x higher concentrations of erlotinib are required to inhibit wild type EGFR versus exon 19 mutant EGFR41, D3 reduction of the IC50 value of erlotinib in Hep3B to within observed patient serum concentrations42 suggests promising, new therapeutic indications for erlotinib-D3 combination in cancers with wild type EGFR.