EGFR and non-small cell lung carcinoma: Two mutations, deletions in exon 19 and the single amino acid substitution L858R in exon 21, often referred to as “classical” EGFR mutations, together account for  ̃85% of observed EGFR mutations in NSCLC (Fig. 1) and confer sensitivity to EGFR tyrosine kinase inhibitors (EGFRi) [[5], [6], [7]].