P-tau217 showed robust correlations with NfL (R = 0.33, (CI: 0.27–0.38), p < 0.0001) and weaker with GFAP (R = 0.03, (CI: −0.027–0.098, p = 0.27), with stronger associations in the MCI (R = 0.47, (CI: 0.31–0.61), p < 0.0001 ) and dementia groups (Dementia (R = 0.33, (CI: −0.01–0.60), p = 0.06) for Nfl and MCI (R = 0.13, (CI: −0.51–0.32), p = 0.15) and Dementia (R = 0.12, (CI: −0.22–0.44), p = 0.5) for GFAP. The gene discussed is GFAP; the disease is dementia.