STK11 and neoplasm: We found that LKB1 expression was significantly related to tumor size (OR 0.515; 95% CI 0.316–0.839; P < 0.01), differentiation (OR 0.643; 95% CI 0.521–0.794; P < 0.001), depth of invasion (OR 0.397; 95% CI 0.319–0.494; P < 0.001), lymph node metastasis (OR 0.487; 95% CI 0.397–0.598; P = 0.01), and TNM stage (OR 0.362; 95% CI 0.293–0.447; P = 0.006).