CXCR2 and colitis: Accordingly, we observed that the expression levels of genes encoding chemokines (Ccl3, Ccl4, and Ccl6), chemokine receptors (Ccr1, Ccr5, Cxcr2, Cxcl1, Cxcl2, and Cxcl13), and inflammatory factors (Mpo, Il-1β, and Il12) were increased in mice with DSS-induced colitis.