Inhibition of EZH2 alters MK polyploidization though CDKi regulation. (A) Heatmap showing differentially expressed CDKi’s in mature MKs (CD41⁺CD42⁺). (B) mRNA expression of CDKN2D (p19) and CDKN1A (p21) in cord blood–derived CD41⁺CD42⁺ cells in the presence of GSK343 (n = 5) and shEZH2 (n = 3 for shEZH2.1 and n = 2 for shEZH2.2). Data were compared using a Student t test with Mann-Whitney correction. (C) mRNA expression of CDKN2D (p19) and CDKN1A (p21) in leukapheresis-derived CD41⁺CD42⁺ cells in the presence of GSK343 (n = 3) at day 9 of culture. Data were compared using a Student t test with Mann-Whitney correction. (D-E) Ploidy analysis in CD41⁺CD42⁺ cells derived from leukapheresis CD34⁺ cells in the presence of GSK343 (n = 4) (D) and shCDKN1A, shCDKN2D, and shCDKN1A+shCDKN2D (n = 4) (E). Data were compared using a Student t test with Mann-Whitney correction. All data represent means ± SEM. *P < .05; **P < .005; ns, not significant.