TLR4 and fungal infectious disease: In less than 10 years after Janeway's proposal, his hypothesis was supported by evidence showing an exquisite susceptibility to fungal infection in Drosophila melanogaster carrying a mutation in a so called “Toll” receptor (Lemaitre et al., 1996) and confirmed by the cloning and functional characterization of a human homologue of “Toll”, now defined as Toll-like receptor-4 (TLR-4) (Medzhitov et al., 1997).