GFAP and X-linked adrenoleukodystrophy: Consistently, logistic regression for assessing the utility of blood GFAP to discriminate the onset of neuroinflammation in X-ALD patients revealed that GFAP is a better predictor for CALD in childhood/adolescence (AUC 0.881, 95% CI 0.757–0.968) than in adulthood (AUC 0.643, 95% CI: 0.503–0.813; Supplementary Figure S2).