The TNFSF13B variant (named BAFF-var) leads to increased levels of serum BAFF, immunoglobulins and circulating B cells, particularly memory B cells, the main reservoir for life-long EBV infection, raising the possibility that BAFF-var might favor an altered EBV-immune system balance. This evidence concerns the gene TNFSF13B and Epstein-Barr virus infection.