Results from a study by Furuya et al. showed that IgA−/− mice were more susceptible than IgA+/+ mice to intranasal F. tularensis LVS infection that started in the second week post infection, despite developing higher levels of anti-LVS total, IgG, and IgM isotype antibodies in bronchoalveolar lavage [128]. This evidence concerns the gene CD40LG and infection.