CTNNB1 and hepatocellular carcinoma: Exon sequencing of 139 HCC found expected mutations in previously described genes like CTNNB1 or TP53 and unexpectedly LoF mutations in ARID2. ARID2 alterations consist in frameshift-inducing insertion or deletion (indels), nonsense mutations, and splice-site mutations with no major hotspot of mutations (Figure 2A).