Figure 4.

Late-outgrowth endothelial progenitor cell colony-forming unit (CFU) number in rheumatoid arthritis (RA) patients and controls. (a) Representative photomicrograph of late-outgrowth CFUs in culture after 15 days from one RA patient (×40 magnification). (b) Increase of CFU number in RA patients (P < 0.05).