To test this hypothesis, we created an animal model that expresses WT-TLR4 (TLR4+/+) in macrophages in the gingiva, but whose liver resident cells are either TLR4+/+ (GFPWT:WT chimeras) or TLR4-/- (GFPWT:TLR4-/- chimeras referred to as GFPWT:KO) by performing adoptive bone marrow transplantation and inducing periodontitis. This evidence concerns the gene TLR4 and periodontitis.