CX3CR1 and colitis: Cx3cr1 is involved in the development and progression of chronic inflammatory diseases, such as colitis and arthritis (Kotani et al., 2013; Rossini et al., 2014; Tarrant et al., 2012) while Cx3cr1 deficiency reduces the severity of these diseases (Niess and Adler, 2010; Rossini et al., 2014; Tarrant et al., 2012).