GFAP and Alzheimer disease: In 1FLADRC, plasma GFAP did not moderate the relationship between AD meta‐ROI volume or memory or executive function (ps > 0.05), though the main effects of higher plasma GFAP and worse cognition were observed independently of AD meta‐ROI volume (GFAP Cogmemory: β [95% CI] = −0.18 [−0.29, −0.08], p < 0.001; AD meta‐ROI Cogmemory: β [95% CI] = 0.54 [0.42, 0.66], p < 0.001; GFAP Cogexecutive: β [95% CI] = −0.16 [−0.27, −0.05], p = 0.02; AD meta‐ROI Cogexecutive: β [95% CI] = 0.41 [0.28, 0.53], p < 0.001).