Genome-wide association studies (GWAS) have shown that SOCS1 single nucleotide polymorphisms (SNPs) are found in a variety of immune diseases, including primary biliary cirrhosis, multiple sclerosis, Crohn’s disease, and celiac disease, strongly suggesting the role of SOCS1 in immune regulation and human immunological diseases.90) Although the phenotypes of SOCS1-deficient mice strongly indicate the important role of SOCS1 in immune tolerance, germline mutations of the SOCS1 gene in humans have only recently been reported. The gene discussed is SOCS1; the disease is Crohn disease.