First, 11 genes that are commonly mutated in HCC (tumour protein p53 [TP53], phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha [PIK3CA], retinoblastoma protein [RB1], cyclin-dependent kinase inhibitor 2A [CDKN2A], tuberous sclerosis-2 [TSC2], β-catenin [CTNNB1], AT-rich interactive domain-containing protein 2 [ARID2], axin 1 [AXIN1], ribosomal protein S6 kinase A3 [RPS6KA3], AT-rich interactive domain-containing protein 1A [ARID1A], and lysine methyltransferase 2D [KMT2D]) were selected. The gene discussed is ARID1A; the disease is hepatocellular carcinoma.