Motivated by the optimistic results attained with a cocktail of DNMT and HDAC inhibitor in context of the anticancer efficacy including the suppression of the tumorigenicity of cancer stem-like cells and enhancing cancer immune therapy [332–336], Yuan et al. designed and synthesized a dual DNMT and HDAC inhibitor C02S (87) (Fig. 12) that demonstrated significant enzymatic inhibitory activities against DNMT1, DNMT3A, DNMT3B and HDAC1. This evidence concerns the gene DNMT3B and cancer.