The first type includes the so-called activating mutations of EGFR, such as deletion of exon 19 (Ex19del) [18] or substitution of L858R in exon 21 [19] (the positions of these loci are shown in Figure 2), which are frequently found in non-small-cell lung cancer (NSCLC) tissue. Here, EGFR is linked to non-small cell lung carcinoma.