The patients with HCC who had high expression levels of MED6 (p = 0.0043), MED15 (p = 0.0039), MED17 (p = 0.011), MED19 (p = 6.8E − 06), MED21 (p = 0.042), MED22 (p = 0.012), MED24 (p = 0.019), and MED25 (p = 0.014) were significantly associated with worse overall survival. The gene discussed is MED21; the disease is hepatocellular carcinoma.