Especially pertinent is the FDA approval of belimumab (trade name Benlysta®), a neutralizing antibody against BAFF, for the treatment of SLE (48), spurred by the success of a randomized double-blind placebo-controlled trial that demonstrated efficacy and safety in SLE patients treated with belimumab over placebo (47). Here, TNFSF13B is linked to systemic lupus erythematosus.