In Drosophila melanogaster (Meigen, 1830), the regulation of antifungal peptides in response to fungal infection primarily relies on the Toll pathway; mutations in the Toll pathway render D. melanogaster more susceptible to fungal infections and impair the inducible production of the antifungal peptide, drosomycin [74]. The gene discussed is TLR4; the disease is fungal infectious disease.