Mean treponemal IgM levels rose with CS severity, peaking in the high-risk group (<i>possible</i> or <i>confirmed proven/highly probable</i> CS: 29.9 ± 20.6 RLU) versus <i>CS less likely</i> (17.5 ± 20.8 RLU) and controls (3.5 ± 0.8 RLU; <i>P</i> < 0.05). The gene discussed is CD40LG; the disease is Cowden syndrome 1.