CHI3L1 and juvenile Huntington disease: Whilst the search for novel fluid biomarkers is ongoing,49 neurofilament light chain has been shown to have great prognostic value,27,28 and total-Tau and YKL-40 have also shown to be elevated in CSF from Huntington’s disease mutation carriers.30,31 We set out to track these three proteins in plasma and CSF from mouse models of Huntington’s disease to provide a translatable fluid biomarkers as a readout for preclinical therapeutic trials.