Further support for the idea was obtained in a recent study, showing a comparable level of protection from experimental arthritis in Cd55-/- and Cd97-/- mice, which might relate to a role of both molecules in the retention of leukocytes in the inflamed synovium [42] Of note, CD55 is the first binding partner that is linked functionally to an adhesion GPCR in vivo[43]. The gene discussed is CD55; the disease is arthritic joint disease.