HTRA2 and hepatocellular carcinoma: HtrA2 has also been recognized as an essential risk factor for overall survival (P=0.01, HR = 1.654, 95% CI 1.128–2.425), disease-specific survival (P=0.004, HR = 2.204, 95% CI 1.294–3.753), and progression-free interval (P=0.007, HR = 1.637, 95% CI 1.145–2.341) of HCC.