Epidermal Growth Factor Receptor Double Activating Mutations Involving Both Exons 19 and 21 Exist in Chinese Non-small Cell Lung Cancer Patients

delE746-A750 + L858R double activating EGFR mutations exist in Chinese NSCLC patients and both locate on the same allele. These patients tend to respond well to TKIs and the sensitivity to TKIs of this double mutated EGFR is enhanced compared with either single mutant. Nonetheless, the alteration in downstream signal transduction of the double mutant remains to be determined.