In contrast, other common tumor-associated CTL targets such as PRAME and NY-ESO-1 are not expressed as commonly as WT1 in AML cell lines and primary samples and often require pretreatment with a hypomethylating agent or histone deacetylase inhibitor to induce sufficient target expression for CTL recognition (60–62). This evidence concerns the gene PRAME and acute myeloid leukemia.