FOXP3 and immune dysregulation-polyendocrinopathy-enteropathy-X-linked syndrome: Therefore, the thrombocytopenia and platelet abnormalities experienced by some patients with IPEX syndrome can be explained by loss of function of FOXP3 [47]; however, this explanation would suggest a concomitant impairment of GARP expression and function on IPEX platelets, an impairment that has not yet been shown.