CCL2 and clostridium difficile infection: Four pathways were identified: the IL-17 signaling pathway consisted of four genes with increased expression (Tnf, Ccl2, Mmp13, and Mmp3) during CDI compared to Cef, while 25 genes with reduced expression were spread between glycolysis/gluconeogenesis metabolism, cholesterol metabolism, and PPAR signaling pathway (Fig. 1D; Fig. S1A through D).