Recent works have found a correlation between GITR and some human pathologies: in the pathogenesis of rheumatoid arthritis (RA), the expression of GITR on macrophages in human RA synovium may enhance inflammatory activation of these cells [47]; in atopic dermatitis, the interaction of GITR with its cognate ligand, GITRL, may perpetuate local inflammation [48]; finally, one polymorphism of GITR gene seems to be associated with Hashimoto's disease prognosis [49]. The gene discussed is TNFRSF18; the disease is rheumatoid arthritis.