NPC2(Niemann Pick C2) is a protein containing a lipid recognition domain. NPC2 protein may function in regulating the transport of cholesterol through the late endosomal/lysosomal system. NPC2 plays a crucial role in regulating the lipid composition of sperm membranes during maturation in the epididymis. This function is vital for proper sperm development and fertility, as alterations in lipid composition can affect membrane fluidity and functionality. Mutations in NPC2 gene can lead to Niemann-Pick disease type C2, a severe hereditary condition characterized by defective lysosomal release of cholesterol, resulting in symptoms such as frontal lobe atrophy and other neurological impairments.