BIRC2 and hepatocellular carcinoma: To explore the relationship between NAP1L1 and BIRC2 proteins and apoptosis, we first identified the differential genes associated with NAP1L1 and BIRC2 in hepatocellular carcinomas in the TCGA database using single-gene-differential-analysis, and then functionally clustered these differential genes using GO/KEGG combined with logFC.