TNFSF13B and lupus nephritis: Belimumab is the anti-B-lymphocyte stimulator (BLyS; also known as BAFF) monoclonal antibody and is approved for the treatment of non-renal SLE based on four successful trials (Furie et al., 2011; Navarra et al., 2011; Stohl et al., 2017; Doria et al., 2018) and for the treatment of lupus nephritis (LN) based on the BLISS-LN trial (Furie et al., 2020).