A Proliferation-inducing Ligand (April)) also known as TNSF13A, Tall-2, and TRDL-1, is a member of the TNF ligand (TNFL) superfamily. April is most similar to B-cell activation factor (BAFF) with which it shares 30% sequence identity, compete for two receptors, TACI and BCMA. APRIL is expressed at...