EGFR and non-small cell lung carcinoma: The two most frequent mutations in EGFR in NSCLC are the L858R point mutation in exon 21, And the proportion of these two types of mutation ranged from 52% [24] to 96% [9] of all identified mutations in exon 19 and 21among 15 chosen studies Thus, the higher proportion of common mutations, the higher sensitivity the mutation specific antibodies would be.