CD40LG and rheumatoid arthritis: To investigate the feasibility of the RA diagnostic model, we employed eight rheumatoid-specific clinical measures (ESR, anti-CCP, anti-streptolysin O [ASO], RF, C-reactive protein [CRP], immunoglobulin-G [IgG], immunoglobulins-A [IgA], and immunoglobulins-M [IgM]) to establish a diagnostic model (VR8) (Figure 3a).