We grouped 65 genes

in risk scores in the context of the GO to summarize biological characteristics of risk score. Not surprisingly, genes involved in signaling transduction are enriched in those whose expression is positively associated with poor prognosis (high risk genes, Supporting Table 2), whereas genes associated with normal this website metabolic functions of liver are enriched in low risk genes (Supporting Table 3). In addition, we used gene expression data from the MSH cohort, for whom many biological characteristics are available.11 Ninety-one patients from the MSH cohort were stratified according to risk score by applying the coefficient and threshold values (8.36) derived from the NCI cohort. All three signaling events (phosphorylation) examined in the previous study with the MSH cohort were significantly associated with the risk score (Supporting Table 4). We found that a high risk score was significantly associated with enriched phosphorylation of AKT (P = 0.003, χ2 test), IGFR1 (P = 2.2 × 10−4, χ2 test), and RPS6 (P = 3.6 × 10−5, χ2 test). Mutation of TP53 is not associated with the risk score (P = 0.93), whereas a high frequency of mutations of CTNNB1 (beta-catenin) was significantly associated with Ku-0059436 concentration a low risk score (23/27 mutations, P = 0.05, χ2 test). To validate the association

between risk score and CTNNB1 mutations in HCC, patients in the INSERM cohort Sitaxentan (n = 57) were stratified by risk score using same 8.36 cutoff threshold.9 Of 17 HCC tumors with CTNNB1 mutations, 16 were in the low-risk group, and this association was statistically significant (Supporting Table 5; P = 0.015, χ2 test). By applying multistep exploration and validation strategy (Supporting Fig. 6), we identified and validated

a risk score based on expression patterns of 65 genes that can easily quantify the likelihood of OS in HCC patients who have undergone surgical resection as the primary treatment. Several lines of evidence strongly support that the risk score is an independent and significant predictor of prognosis. First, the risk score was the significant predictive factor for OS in the combined validation cohort in multivariate analysis (Table 3). Second, the risk score can identify high-risk patients in both early stage HCC (BCLC stage A) and those with intermediate or advanced stage (BCLC stage B and C) (Fig. 4). The strength and independence of the risk score over the current staging systems remained significant even when the AJCC staging system was applied (Supporting Fig. 3). Third, the risk score identified a poor prognosis patients without vasculature invasion, who are typically considered as good prognosis patients (Supporting Fig. 5). Fourth, the risk score was the most significant predictor of 3-year survival of patients in ROC analysis (Fig. 3).