PTGER4 and multiple sclerosis: PTGER4 has been previously found to be associated with Crohn's disease [9], [14], [15], [16], reported as “suggestive signal” in a meta-analysis of MS GWAS [17], and also reported as genome-wide significant for MS in a recent GWAS by the International Multiple Sclerosis Genetics Consortium/Wellcome Trust Case Control Consortium.