To confirm that autophagy protects against sorafenib toxicity in HCC cells, we investigated whether autophagy inhibition enhances the sensitivity of HCC cells to sorafenib using 3-methyladenine (3-MA, an autophagy inhibitor) or small interfering RNA (siRNA) targeting ULK1, which is a critical molecule in autophagy formation. The gene discussed is ULK1; the disease is hepatocellular carcinoma.