PIK3CA and hepatocellular carcinoma: Consistent with the genomic analysis of liver tissues from TCGA HCC cohort (Cancer Genome Atlas Research Network 2017), the top 5 highest mutations occur in TERT promoter (27.5%), TP53 (21.3%), CTNNB1 (13.1%), PIK3CA (0.2%), and NFE2L2 (0.2%), suggesting these ctDNA mutations may serve as promising non-invasive markers for HCC diagnosis.