TBXT and Alzheimer disease: In addition, CSF p‐tau235 strongly correlated with all three core CSF biomarkers for AD, specifically a negative correlation with Aβ1–42 (rS = −0.77, P < 0.0001) and positive correlations with t‐tau (rS = 0.85, P < 0.0001) and p‐tau181 (rS = 0.78, P < 0.0001) (Appendix Table S4).