CHI3L1 and Alzheimer disease: In order to investigate if microglial markers could differentiate between AD and controls, and secondly between stable MCI and those progressing to AD, the Olsson et al. study quantified YKL-40 and sCD14 in CSF from 96 AD patients, 65 healthy controls, and 170 patients with MCI from baseline and over 5.7 years (Olsson et al., 2013).