We have performed analysis depending on serological status; for AChRAb(+) MG patients treated with CS within last three months, mean BAFF levels were 730.5 ± 295.8 vs. 930.7 ± 239.5 for untreated (p ≤ 0.001); for patients treated with CS whenever in the past, mean BAFF levels amounted 778.8 ± 301.0 vs. 907.8 ± 243.0 pg/ml for untreated (p = 0.002). This evidence concerns the gene TNFSF13B and myasthenia gravis.