SLC22A4 and inflammatory bowel disease: In IBD, there is a correlation with two risk haplotypes: IGR2198a_1 (rs11739135) and IGR2096a_1 (rs12521868), with the polymorphisms 1672C → T (L503F) of SLC22A4 (OCTN1) and −207 g → C of the SLC22A5 promoter (OCTN2) and with various polymorphisms of the P4HA2 and IRF-1 genes.