Increased S100β is indicative of neurodegeneration (Rothermundt et al., 2003) and vCSF levels were significantly higher in PMS cases versus controls, (Wilcoxon Ranked Sum Test p = .040, mean and standard deviation in PMS cases was 0.99 ± 1.0 and 0.17 ± 0.48 in controls (Fig. 3a and Supplementary Table 4), with 14 out of 27 PMS cases (51%) and 12 out of 15 controls (80%) exhibiting undetectable levels. The gene discussed is S100B; the disease is premenstrual tension.