a trend toward significancep = 0.052
However, the CSF TTR × diagnosis interaction term reached significance for t-Tau ( p = 0.013), p-Tau181 ( p = 0.020), and NfL ( p = 0.006), and showed a trend toward significance for Aβ40 ( p = 0.052), indicating that the strength and direction of associations differ across diagnostic stages (Fig. 2 A-D).