Innate immunity plays an important role for fungal recognition and initiation of fungicidal activity. We hypothesize that subtle differences in different molecules of innate immunity may contribute to either the predisposition or clinical course of infection with Blastomycosis dermatitidis. To test this hypothesis, we propose to analyze the allelic frequencies of 15 different genes (mannose binding lectin, Fc-gamma receptor IIa and IIb, Fc-gamma receptors IIIa and IIIb, myeloperoxidase, tumor necrosis factor-alpha and -beta, interleukin 1A and 1B, interleukin-1 receptor antagonist, interleukin-10, NRAMP-1, chitotriosidase, and chemokine receptor 5) and their intragenic polymorphic forms and to compare this data to the incidence and severity of Blastomycosis dermatitidis infection. With this study we hope to identify a group of molecules of innate immunity which influence the risk and severity of invasive Blastomycosis dermatitidis infection.