Figure 4 :Expected P-value in follow-up studies of rs6897932, the IL7R–associated SNP The red line indicates the expected P-value and the dotted lines the 95% confi dence intervals on this estimate (plotted as the negative log). It can thus be expected that 95% of the time the observed P-value will fall within this space. The horizontal dotted line indicates the nominal 5% signifi cance level. Reprinted from Brain, Vol. 131, 3118-31, Copyright (2008), with permission from Oxford University Press.