To test whether IL-21 could be involved in the innate immune response to HSV-2 infections we investigated IL-21 and IL-21R expression at the site of infection on day 1-3 p.i. We measured IL-21 protein in vaginal washes and IL-21 and IL-21R mRNA levels in vaginal tissue from C57BL/6 WT mice infected intra-vaginally with HSV-2 and from u.i. controls. The gene discussed is IL21; the disease is infection.