EGFR mutations were more common in patients who were female (56.5 vs. 43.5%; p < 0.001), non-smokers (77.4 vs. 22.6%; p < 0.001), patients with moderately differentiated tumors (27.8 vs. 50.0%, and 22.2%; p < 0.015), patients with TTF-1 positive expression (95.5 vs. 4.5%; p < 0.021), and patients with lung adenocarcinoma of the right upper lobe (Table 1). Here, TTF1 is linked to lung adenocarcinoma.