The fourth BAFF antagonist, telitacicept (RC18), a recombinant fusion protein of the human IgG1 Fc domain and TACI receptor extracellular domain that binds to BAFF, is in the phase II trial recruitment phase in the treatment of IgA nephropathy (NCT04905212). This evidence concerns the gene TNFSF13B and IgA glomerulonephritis.