CXCL2 and infection: Our results showed that LPS stimulated an inflammatory response characterized by potent induction of mRNA expression for pro-inflammatory cytokines, such as Il1b, Tnf, Il6, and Ifng. Consistent with our mRNA data, LPS increased the tissue concentrations of IL1B, IL6, and IL10, as well as IL1A, CCL2 and CXCL2, which may play important roles in immune cell recruitment to the epididymis upon infection by Gram-negative bacteria.