To further investigate the link between lysosomal dysfunction, altered cholesterol metabolism and accumulation of Aβ/APP-CTFs we treated CHO cells and human neuroblastoma SH-SY5Y cells with a general lysosomal inhibitor Leupeptin and ammonium chloride (Leu/NH4Cl), cathepsin B/L inhibitor (PADK) or cathepsin D inhibitor Pepstatin A (PepA). This evidence concerns the gene CTSD and neuroblastoma.