Quantification of Tregs infiltrating the intestinal mucosa from SCT patients. Gut biopsies were endoscopically taken from transplanted patients with clinically suspected intestinal GVHD. DNA was isolated from 2 gut biopsies each taken from patients with cGVHD (n = 6; 4 females/2 males), aGVHD (n = 8; 2 females/6 males), and without any histologic signs of GVHD (n = 4; 3 females/1 male). Percentage of FOXP3 Treg specific demethylation region demethylation levels was determined by quantitative PCR (“DNA demethylation analysis of the foxp3 gene locus in gut biopsie”). *P < .05 (Student t test).