EGFR and small cell lung carcinoma: Epidermal growth factor receptor (EGFR)is a transmembrane protein,featuring an extracellular EGF binding domain and an intracellulartyrosine kinase domain, responsible for the transduction of signalspromoting cell proliferation.1 Hyper-activatingmutations in the kinase domain of EGFR, at the level of exon 19 (del19)or exon 21 (L858R mutation), have been observed in at least 50% ofnon-small-cell lung cancer (NSCLC).2 Thesealterations promote NSCLC insurgence and progression as their presenceresults in the constitutive activation of EGFR.3