IDH1 and leukemia: Similarly, interface clusters were enriched for alterations in DNA methylating factors that are typical of less differentiated leukemias [13, 41, 42], with DNMT3A, IDH1 and IDH2 mutated T-ALLs being confined to cluster 2 (p = 0.0267), but PTEN mutations that normally segregate with phenotypically mature leukemias [43] were significantly more common in AML-like T-ALLs than in other T-ALL cases (50% v 7.1%, p = 0.0287).