NOD2 and Crohn disease: The synthetic association paradigm is supported [7] by the well-known association between Crohn's disease and NOD2[8], where three rare coding variants (G881R – MAF:0.04, R675W – MAF:0.01, and L980fs – MAF:0.02) confer high risk for Crohn's (ORs for a carrier and homozygote are 3 and 38, respectively) [9].