Low-dose chidamide increased CTLA4 mRNA expression, and CTLA4 shRNA interference prevented the platelet count from improving with chidamide treatment. (A) Low-dose chidamide increased relative mRNA expression of the CTLA4 gene in active ITP mice. (B) CTLA4 shRNA interference decreased CTLA4 gene expression in the CTLA4 shRNA group and in the CTLA4 shRNA + chidamide group in the active ITP mice. (C-E) CTLA4 shRNA transference offset the low-dose chidamide treatment in active ITP mice on days 14 and 21. *P < .05.