At 8.3-weeks post-HDTVi, there was an increase in gross tumor burden and significant increase in liver weight, LW/BW, and spleen weight in β-M-POU2F1 + αCD3 versus β-M-POU2F1 + IgG animals (Supplementary Fig. 20c–f), suggesting an immune-dependent role for POU2F1-mediated tumor regression in CTNNB1-mutated HCC. Here, CTNNB1 is linked to hepatocellular carcinoma.