TNFAIP3 and Behcet disease: The phenotype and severity of HA20 in our survey differed, even among cases with the same variantof TNFAIP3. HLA alleles affecting T cells are reportedly a factor influencing thephenotypes of Behcet’s spectrum disorders (e.g. recurrent aphthous stomatitis, PFAPA, and BD), including severity and tissue involvement, with the strongest association between HLA and BD (22).