Together, biomarker data from this NILVAD trial suggest that cognitive improvement in mild AD subjects after treatment with nilvadipine corresponds to an increase in CSF Aβ42/Aβ40 ratios, whereas worsening of cognition in moderate AD subjects is paralleled by a decrease in CSF Aβ42/Aβ40 ratios and higher total tau, ptau, YKL-40 and neurogranin levels. This evidence concerns the gene CHI3L1 and Alzheimer disease.