research Effect of PTPN22, FAS/FASL, IL2RA and CTLA4 genetic polymorphisms on the risk of developing alopecia areata: A systematic review of the literature and meta-analysis
This study suggests that the T allele of the SNP rs2476601 in the PTPN22 gene may increase the risk of alopecia areata, although further studies are necessary to validate this finding across different populations.

