ZFP36 and thrombotic thrombocytopenic purpura: To further confirm the role of IL-27 in IFN-γ production by Zfp36−/− CD8 T-cells, we generated TTP and WSX-1 double knockout mice (TTP/WSX-1 DKO), isolated splenocytes from WT, IL27ra−/−, Zfp36−/− and TTP/WSX-1 DKO mice, and measured IFN-γ production.