In this study, we deepened our understanding of VD regulating HCC progression and enhancing the effectiveness of immune therapy in HCC, by elucidating the specific molecular mechanism by which VD exerts its anti-tumor effect in HCC; VD promotes nuclear translocation of VDR-YY1 interaction, leading to transcriptional activation of VDBP. The gene discussed is YY1; the disease is hepatocellular carcinoma.