In the UCD, the numbers of FOXP3+ T-reg (mean 26.54 ± 26.87) were compared, respectively, to the numbers of T-reg in MCD cases as a whole (mean 20.27 ± 12.11), in iMCD (mean 17.33 ± 12.04), and in HHV8+ MCD (mean 24.67 ± 11.83). This evidence concerns the gene FOXP3 and urea cycle disorder.