MAPK1 and myeloid sarcoma: The two most significant associations in this study for CD were initially identified in a meta-analysis of European-descent populations for MS where the opposite alleles for rs1323292 (A) and MAPK1 rs2283792 (C) contributed to MS risk (OR = 1.12 and OR = 1.10, respectively; International Multiple Sclerosis Genetics Consortium et al., 2011).