CHIT1 and lysosomal storage disease: In particular, its expression is more pronounced in patients with abdominal organ localizations (the liver and spleen, in our population), probably due to an overexpression by activated resident macrophages; this data suggests that chitotriosidase may be a reliable marker of activation of reticuloendothelial system in sarcoidosis, as previously reported in patients with lysosomal storage disease [33].