TNF and rheumatoid arthritis: Further evidence of TNF-mediated effect on the number of circulating EPCs was provided by Ablin et al. [28] who demonstrated ex vivo a positive influence of infliximab administration; the authors investigated the effect of a single dose of the anti-TNF drug in 14 RA patients who were already treated with infliximab and methotrexate and observed a significant increase of EPC number and adhesive function 14 days after drug infusion.