SPP2 and hepatocellular carcinoma: As the forest plot displayed in Fig. 3A, 29 PRGs with prognostic values were identified, and except for SPP2 (HR: 0.876, 95%CI: 0.817–0.939) and GNA14 (HR: 0.558, 95%CI: 0.406–0.767), the remaining PRGs were regarded as risk factors for HCC patients in the training set.