PTPN22 and inflammatory bowel disease: Of special interest are the findings in the UC patient group: even though in most GWAS no association of PTPN22 SNP rs2476601 with UC was found[11, 12], and one study in a Danish IBD cohort even found reduced risk to develop UC upon presence of SNP rs2476601[9], our study in contrast suggests that the A-allele might have a disease-promoting role.