Monocytes, in particular, are recruited during the early stage of infection and respond to MIP-1α, interleukin (IL)-6, IL-8, CCL2, and CCL5, which are secreted by infected epithelial cells and innate immune cells in close vicinity, as demonstrated in murine in vivo experiments and human in vitro systems (34, 35). The gene discussed is CCL2; the disease is infection.