Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK or TNFSF12), and its cognate receptor, Fn14 (TNFRSF12A), have been shown to play an important role in SLE in general [11,12,13] and NPSLE in particular. This evidence concerns the gene TNFRSF12A and systemic lupus erythematosus.