The drugs that have received FDA approval for blood cancer treatment since 2011 inhibit the catalytic activity of such enzymes as histone deacetylase (HDAC), isocitrate dehydrogenases (IDHs), enhancers of zeste homolog 2 (EZH2), and deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) methyltransferase (Figure 4). This evidence concerns the gene EZH2 and hematopoietic and lymphoid system neoplasm.