EGFR and lung cancer: A study revealed that among lung cancer patients,37% (36/98) of the samples presented with EGFR mutations, of which 72.2% had exon 19 deletions and 27.8% had exon 21 substitution mutations [17] Mutations in driver genes such as EGFR, ALK, and MET render patients to be sensitive to targeted agents while decreasing their sensitivity to PD-1 monotherapy.