Many of the autoimmune diseases such as rheumatoid arthritis, inflammatory bowel diseases, psoriatic arthritis and system lupus erythematosus, viral diseases and, some cancers are characterized with elevated levels of "immunocytokine" gene expression, including, tumor necrosis factor-α, various interleukins, cytotoxic T-cell antigen-4, B-cell activating factor. Here, TNFSF13B is linked to psoriatic arthritis.