Importantly, whole genome DNA methylation data for two independent cohorts (NNOPHO = 101, NALLIC-BFM = 109) of pediatric T-ALL patients (30, 35, 36) revealed hypermethylation of the TET2 promoter in a subset of patients (9/101 Nordic Society for Pediatric Hematology and Oncology [NOPHO]; 8/109 International Berlin-Frankfurt-Munster Study Group trials 2009 [ALL IC-BFM]) (Fig. 1 I and J), suggesting one mechanism of TET2 silencing may be through aberrant DNA methylation. Here, TET2 is linked to acute lymphoblastic leukemia.