CD22 and systemic lupus erythematosus: Another possible option is B-cell suppression by either anti-CD22 antibody (epratuzumab) or antibody blocking of the Lympho-Stat-B, B-cell Activating Factor (BAFF) or a proliferation-inducing ligand (APRIL), which are under investigation for patients with rheumatoid arthritis and lupus but are without application to HT yet [30,31,32,33].