The facts that both SNPs rs3803800 [A] and rs11552708 [G] in TNFSF13 were reported to be associated with the susceptibility to the Systemic Lupus Erythematosus (SLE) in the Japanese population and that high serum APRIL was detected in the sera of individuals with the rs3803800 [A]–rs11552708 [G] haplotype [18] further support the significance of these SNPs in the regulation of immunoglobulin production. The gene discussed is TNFSF13; the disease is systemic lupus erythematosus.