TP53 and hepatocellular carcinoma: Common genomic alterations detectable in ctDNA include single-nucleotide variations (mainly somatic variations) in the genes TP53, KRAS, and CCND1; copy number variations involving genes such as CDK6, EFGR, MYC, and BRAF; DNA methylation changes in genes such as RASSF1A, SEPT9, KMT2C, and CCNA2; homozygous mutations (e.g., CDKN2A and AXIN1); and large chromosomal rearrangements, which are especially implicated in HCC [117].