CXXC4 and leukemia: Our studies also suggest a bimodal function of TET2—when TET2 binds to CXXC4/CXXC5, it mediates DNA 5mC oxidation at the enhancer; however, when recruited by RNA-binding proteins such as PSPC1, TET2 mediates chromatin-associated repeat RNA m5C oxidation; this RNA m5C oxidation activity by TET2 dictates the global chromatin regulation in mES cells, HPSCs and leukaemia cells.