NPC1 and cerebellar ataxia: We also investigated whether other experimental NPC therapies would have similar therapeutic efficacy in Tangier disease cells as it may provide insights into the underlying pathogenic/convergent mechanisms.9 We therefore examined the effects of 2‐hydroxypropyl‐β‐cyclodextrin (HPβCD), which reduces cholesterol and sphingolipid storage and is currently in clinical trials for NPC1,23 as well as acetyl‐DL‐leucine (ADLL), which has previously been shown to improve symptoms in patients with cerebellar ataxia.24