Increased expression of IL12B mRNA transcribed from the risk haplotype for Crohn’s disease is a risk factor for disease relapse in Japanese patients

Background IL12B is a promising candidate for a susceptibility gene in Crohn’s disease (CD). The aim of this study was to perform a candidate gene analysis of IL12B in Japanese CD patients, investigate whether the genotype is associated with disease phenotypes, and determine how the risk allele affects susceptibility to CD.