File:Ijms-22-06600-g001-550.webp

English: Figure 1. Altered cholesterol trafficking in Niemann–Pick disease type C. (A) In normal conditions, lipoprotein cholesterol particles bind to cell surface receptors and are internalized in the late endosome/lysosome system. In the presence of NPC1 and NPC2 proteins, unesterified cholesterol is transported from the late endosomal/lysosomal system to the Golgi complex and endoplasmic reticulum, where it is processed and used for other reactions. (B) In the absence of NPC1 or NPC2, unesterified cholesterol accumulates in the late endosomal/lysosomal system, resulting in deficiencies in the intracellular compartments for which it was intended.