EGFR and squamous cell lung carcinoma: Among the 129 patients who did not undergo EGFR testing via tissue biopsy, the reasons were distributed as follows: 16 patients (12.4%) had benign histology, 20 (15.5%) had early-stage disease, 20 (15.5%) had insufficient or inadequate tissue for molecular testing, 14 (10.9%) had either small-cell lung cancer (SCLC) or were heavy smokers with squamous cell carcinoma of the lung, 14 (10.9%) had non-lung primary tumors, 13 (10.1%) were either unfit for or declined tissue biopsy, and in 29 cases (22.5%), the reason for not performing molecular testing was unspecified (Figure 1).