FCGR3A and systemic lupus erythematosus: In equivalent assays comparing RTX and OBZ, after 24 h of incubation in the absence of mAbs, there was no significant difference in the frequency of NK cells, CD107a+ NK cells, CD16+ NK cells or B cells between patients with RA (n = 18) and SLE (n = 23) (Fig. 3A).