The models of equine placentitis involving the inoculation of pathogenic bacteria (Streptococcus equi subspecies zooepidemicus, Escherichia coli, and/or beta-hemolytic Streptococcus dysgalactiae) [4,29,72,73,74] have demonstrated that infection-induced inflammation activates a complex signaling network, which leads to the production of IL-1β, IL-6, TNFα [29,30], IL-8 [2,75], and prostaglandins E2 and F2 [31]. The gene discussed is IL6; the disease is infection.