Several variations of the ABCB1/MDR1 gene have been associated with increased susceptibility to UC.186 Mice deficient in MDR1α develop spontaneous chronic colitis that resembles human UC.187 Commensal bacteria drive the inflammatory process and changes in the commensal composition due to lack of the MDR1α transporter have recently been described,188 but the innate immune mechanisms functionally involved in modulating disease have not been well defined yet. Here, ABCB1 is linked to Chronic colitis.