We found that TET1 mRNA expression levels are elevated (1.483-fold, P = 3.63 × 10−40), while TET2 expression levels are lower (1.226-fold, P = 1.0) in clinical T-ALL (n = 174) than in normal PBMCs (n = 74), which is consistent with our findings in cell lines. This evidence concerns the gene TET2 and acute lymphoblastic leukemia.