PTPN2 and psoriasis: Outside of the TNFAIP3 gene, the top finding for the TNFAIP3 pQTL analysis of high-quality NGS variant data within AxSpA cases was rs78943928, a SNP residing within 30 kbp 3′ of the protein tyrosine phosphatase non-receptor-type encoding gene, PTPN2. This region immediately downstream of PTPN2 has been strongly implicated by GWAS in a number of systemic inflammatory diseases including psoriasis and IBD (17, 66).