EGFR and lung cancer: In 344 (85.8%) patients, EBUS-TBNA was performed for the first cell type diagnosis in stages IIIB and IV lung cancer, and in 57 (14.2%) patients, the procedure was performed after an initial established pathological diagnosis for tissue sampling for molecular analysis including the epidermal growth factor (EGFR) mutational profile, anaplastic lymphoma kinase (ALK) fusion genes, and mesenchymal-epithelial transition (MET) protooncogene amplification.