CHI3L2 has been detected in macrophages [17]; curiously, it has been reported in neuronal cells from the cerebral cortex (https://www.proteinatlas.org/ENSG00000064886-CHI3L2/tissue/cerebral+cortex#img), but its expression in ALS tissues has not been described so far. Here, CHI3L2 is linked to amyotrophic lateral sclerosis.