The data show that although chronic Δ9-THC treatment decreased the production of these two cytokines, the increased severity of the Candida infection in Δ9-THC treated mice given a second challenge with C. albicans could only be correlated with decreased IFN-γ production, since serum IL-12p40 serum levels were also significantly decreased in the mice given a primary, acute infection with C. albicans and treated with Δ9-THC. The gene discussed is IFNG; the disease is candidiasis.