Serum eNAMPT levels were significantly increased in RA patients than in healthy controls (P = 0.026). Of note, eNAMPT levels of RA patients at week 16 of rituximab treatment were close to those of controls (P = 0.086). In addition, serum eNAMPT levels correlated positively with the total number of B cells (rs = 0.417, P = 0.025). However, eNAMPT levels did not correlate with DAS28 (rs = −0.021, P = 0.913), with CRP (rs = 0.091, P = 0.640), or with IgM-RF levels (rs = −0.276, P = 0.147). The gene discussed is CD40LG; the disease is rheumatoid arthritis.