Figure 4.

(a) Biologic activity and (b) neutralization of BLyS/APRIL HTs compared with those of BLyS and APRIL in B cell-proliferation assays. BLyS, APRIL, and heterotrimers were used at concentrations of 1 nMol/L, 3 nMol/L, and 10 nMol/L, respectively. APRIL, a proliferation-inducing ligand; BAFF-R, BAFF receptor; BCMA, B cell-maturation antigen; BLyS, B-lymphocyte stimulator; CPM, counts per minute; EC₅₀, 50% effective concentration; HT, heterotrimer; IC₅₀, 50% inhibition concentration; Ig, immunoglobulin; TACI, transmembrane activator and CAML interactor.