In an experimental model of rheumatoid arthritis, we recently determined that CD248KO/KO mice and mice lacking the cytoplasmic domain of CD248 (CD248CyD/CyD mice) develop less severe arthritis than CD248WT/WT mice, the differential response likely due to alterations in synovial fibroblast function [32]. This evidence concerns the gene CD248 and arthritic joint disease.