STK4 and non-small cell lung carcinoma: In clinical studies, miR‐18a expression strongly correlated with clinical TNM stage, tumor differentiation and regional lymph node metastasis (P < 0.005), and miR‐18a upregulation is negatively associated with the clinical response of NSCLC because it decreases the sensitivity of cells to radiation by activating the serine/threonine‐protein kinase 4 (STK4) pathway 15.