background: regulatory cd4+t (treg) cells are effective in maintaining immune tolerance. objective: to investigate single nucleotide polymorphisms (snps) of transforming growth factor β-1 (tgf-β1) and forkhead box protein 3 (foxp3) genes in iranian patients with allergic rhinitis (ar). methods: variations at codons 10 and 25 of tgf-β1 and foxp3 at positions -3279 a>c and -924 a>g were evaluated...