Data set

We downloaded the gene expression microarray containing HCC tissue and normal control tissue or paracancerous normal tissue from The Cancer Genome Atlas (TCGA, https://cancergenome.nih.gov) and the Gene Expression Omnibus (GEO; https://www.ncbi.nlm.nih.gov/geo), and obtained RNA-sequencing (RNA-seq) transcriptome data, tumor mutation simple-nucleotide variant (SNV) data, and related clinical data of primary HCC patients. Using VarScan software, we counted the base mutation number, calculated the mutation number per trillion base of each sample, obtained the resultant mutation load, and further determined the relationship between mutation load and overall survival (OS).