TET2 and acute lymphoblastic leukemia: ALL may feature somatic mutations in epigenetic regulators such as DNA methylation modifiers (e.g., DNMT3A, TET2, IDH1, and IDH2), histone modifiers (e.g., members of polycomb repressive complex 2 [PRC2], such as SUZ12, EZH2, EED, and EP300) and histone methyltransferases (e.g., KMT2D(MLL2) and WHSC1) [11,24].