EGFR and lung adenocarcinoma: Substitution of EGFR G719, the first residue of this motif, to serine, cysteine, or alanine, has been observed in lung adenocarcinomas (~1%), and one G719S mutant and four G724S mutants have been reported in colorectal carcinomas that were sequenced for EGFR (Figure 1C)[18,29] (COSMIC database).