Indeed, CEP-33779 significantly reduced several histological parameters that demonstrated improvement in arthritis, including matrix erosion, subchondral osteolysis, osteogenesis, synovial hyperplasia, vasculitis, and synovial inflammation.188 These results indicated that JAK2 took part in the pathogenesis of RA, and inhibition of JAK2 could treat RA by inhibiting the generation of cytokines and the T and B-lymphocytes activation. Here, JAK2 is linked to rheumatoid arthritis.