Order of authorship in the original publication: Lemaitre, Nicolas,... Hoffmann.  This paper represented the foundation of molecular immunology. Hoffmann and colleagues found that flies with mutated Toll genes were unable to mount an immune response when infected with Aspergillus fungus. They realized that Toll genes that code for a receptor complex (Toll-like receptor) are responsible for sensing pathogens, and that in mutant flies which cannot produce the receptor complex, the Aspergillus fungi are not sensed, and the immune system is not activated, causing the fly to be overwhelmed with a massive infection and die. The authors elucidated a very complex molecular cellular pathway activated by Toll once a pathogen is sensed, leading to gene transcription encoding a novel peptide antifungal protein named Drosomycin made by the fly.

Full text available from cell.com at this link.

(Thanks to Juan Weiss for this reference and its interpretation.)