IFNA17 and Aicardi-Goutieres syndrome: CSF IFN-α concentrations in AGS were significantly higher than paired blood (p < 0.005, Figure 1D), with median CSF IFN-α concentrations ∼300 times higher than healthy control CSF (552 fg/mL versus 1.74 fg/mL, respectively, Figures 1B–1D; Table S1).