MS4A1 and systemic lupus erythematosus: Rituximab was approved by the Food and Drug Administration in 1997 for non-Hodgkin’s lymphoma and has since been used in an array of autoimmune diseases, including SLE with lupus nephritis and rheumatoid arthritis.12,13 The benefits of rituximab include its selective B-cell depletion, as the CD20 antigen is not found on other plasma cells or normal tissue.