TNFSF13B and myeloid sarcoma: The median (interquartile range [IQR]) plasma BAFF level in patients with MS was 1041 pg/ml (884–1223 pg/ml), with plasma BAFF levels of 1007 pg/ml (832–1129 pg/ml) in the rRRMS group, 1007 pg/ml (960–1062 pg/ml) in the rrRRMS group, and 1211 pg/ml (974–1391 pg/ml) in the sRRMS group.