CD4 and ataxia telangiectasia: In addition, CD4+ T cells play a regulatory role in the immune response to AITD, and HLA-DR expression – commonly associated with T cell activation – indicates its involvement in immune regulation and disease control in AH.[47] Our findings indicate that HLA-DR+ T cells are associated with a reduced risk of AT, which aligns with the observations reported by Cao et al.[47] Nonetheless, further research is required to fully understand the underlying mechanisms and to identify potential therapeutic targets.