CD19 and systemic lupus erythematosus: Recently, we analyzed data from three phase III RCTs of belimumab i.e., BLISS-76 (NCT00410384) (7), BLISS-SC (NCT01484496) (114), and BLISS Northeast Asia (NEA; NCT01345253) (115) and pinpointed specific relative to baseline percentage changes across different circulating CD19+ B cell and plasma cell subsets occurring in SLE patients after treatment commencement for active disease with standard therapy with or without add-on belimumab to be associated with treatment response (116) or disease flares (117).