The second novel CD association is seen at rs9858542 (P=7.7×10-7), a synonymous coding SNP within the BSN (bassoon) gene on chromosome 3p21. BSN is thought to encode a scaffold protein expressed in brain and involved in neurotransmitter release; a more plausible regional candidate is MST1 (macrophage stimulating 1), which encodes a protein influencing motile activity and phagocytosis by resident peritoneal macrophages68.
