IL13 and infection: The levels of several pro-inflammatory cytokines (IL-8, IL-15, IL-18, IFN- γ, and RANTES) and the immunomodulatory molecule IL-13 were significantly higher in the seminal plasma of macaques during the primary infection (Mann-Whitney test, p = 0.001, 0.0006, 0.01, 0.02, 0.0002, and 0.03, respectively) than that of uninfected macaques (Figure 1C and Table 1).