ENTPD1 and rheumatoid arthritis: Lastly, within R-RA patients, the percentage of B CD39−CD73+ cells demonstrated a negative correlation with CRP (r = −0.490 and p = 0.03), whereas the percentage of B CD39+CD73− cells showed a positive correlation with CRP (r = 0.495 and p = 0.03) (Figure 3b).