To determine the role of platelet-derived miR-223 to KD vasculitis in vivo, the platelet-specific miR-223 knockout mice (PF4-miR-223 KO, PF4-cre: miR-223flox/flox) were successfully constructed, LCWE was intraperitoneally injected (i.p) to establish KD murine model. The gene discussed is PF4; the disease is vasculitis.