TNFSF13B and myeloid sarcoma: A recent GWAS has identified a variant of the TNFSF13B gene encoding the cytokine B-cell activating factor (BAFF) involved in B-cell activation, differentiation, and survival, that is more common in Sardinia, an Italian region with one of the highest MS prevalence rates worldwide, and is associated with an increased risk of developing MS (110).