CRP and rheumatoid arthritis: The most likely explanation for the differences seen between the current study and that of Suk Danik et al. (2006) is that any effect of the genetic markers on CRP levels is less important in more-active disease; in the current study of RA patients with longstanding (median, 12 years) disease, CRP levels were much higher (median CRP, 34 mg/L (IQR, 17, 63), Table 1; see Additional File 1).