In November 2009, Human Genome Sciences and Glaxo‐Smith Kline [HGS (Rockville, Maryland) and GSK, respectively] announced that Belimumab, a neutralizing antibody to the tumour necrosis factor (TNF)‐like ligand, B‐cell activating factor (BAFF belonging to the TNF family, also named BLyS), met the primary endpoints in two phase III clinical trials in systemic lupus erythematosus (SLE, lupus). In March 2011, Belimumab was approved by the US Federal Drug Agency for treatment of SLE patients; this was followed in May with approval by the European Medicines Agency for use in the European Union. This is an exciting development as it is the first successful late‐stage clinical trial in SLE in over 40 years. In the light of this breakthrough, we review the key data and research outcomes and examine how blocking BAFF in patients with SLE significantly improves clinical outcomes. © 2012 IUBMB IUBMB Life, 64(7): 595–602, 2012