TET2 and leukemia: The TET2 enzyme catalyzes DNA demethylation by converting 5′-methylcytosine to 5′-hydroxymethylcytosine, and loss or attenuation of TET2 function leads to a somatically acquired global genomic hypermethylation and transcriptional and phenotypic reprogramming underpinning the development of a leukemia phenotype (7).