FOXP3 and Crouzon syndrome-acanthosis nigricans syndrome: In a study of urinary Foxp3 mRNA and other T cell markers at the time of renal biopsy (257), the mean ratio of Foxp3 mRNA to 18S ribosomal RNA copies is higher in urine from RT patients with acute rejection (n=36) than those with chronic allograft nephropathy (n=18) or normal biopsies (n=29).