During HCC, malignant cells produce CCL22 and recruit CCR4+ Tregs which facilitate the immune escape of malignant cells [19]. Since CCR4 is mainly expressed on Th2 cells and Tregs, which are responsible for immunosuppressive microenvironment, anti-CCR4 antibodies such as mogamulizumab are being used to enhance anti-cancer immunity [20]. This evidence concerns the gene CCL22 and cancer.