The correlation between nine protein-coding genes and patient survival was further cross-validated through the K–M plotter which consists of HCC cohort from TCGA database25,26 (http://www.kmplot.com/), and NT5DC2, UBE2C and hepsin were identified as candidate genes for further study (Fig. 1b, c). The gene discussed is HPN; the disease is hepatocellular carcinoma.