EZH2 and hematologic disorder: CHIP is defined as follows: (1) the presence in peripheral blood of hematopoietic cells with somatic mutations known to be responsible for hematologic malignancies (including the MPNs), such as JAK2 V7617F, TET2, ASXL1, EZH2, IDH1, and DNMT3A; (2) having variant allele frequencies (VAF) of 2% or higher; (3) the absence of clinically overt hematologic malignancies (including MPNs); and (4) the absence of criteria for other preleukemic states [4].