NPC1 and acute lymphoblastic leukemia: Relative to untreated Npc1−/− mice, the life span of animals treated from weaning was modestly but significantly increased by 8 days (9.1%) with ALL treatment (P = 0.0334), 4 days with ADLL (P = 0.0305) (4.5%) and was not changed with ADL (P = 0.6908) (Fig. 1G), therefore displaying l-enantiomer selectivity.