CHI3L1 and Alzheimer disease: The only published study reported data from the first completed open-label phase II study (NCT03748706), which—after 28 days of PTI-125 treatment—showed a significant reduction in some core markers of AD pathology (total tau, p-tau181 in CSF and plasma), neurodegeneration (neurofilament light chain, neurogranin in CSF and plasma) and neuroinflammation (YKL-40, IL-6, IL-1β and TNFα in CSF) [44].