A prospective trial evaluating COS-induced immune changes in healthy, infertile women demonstrated transient alterations in B-cell subsets but found no significant changes in BAFF levels, anti-nuclear antibody titres or immunoglobulin concentrations during or after stimulation [4], suggesting that whilst COS induces temporary immune modulation, it does not significantly activate autoimmunity in immunologically normal individuals. This evidence concerns the gene TNFSF13B and Autoimmunity.