Plays a role as a mediator in the endoplasmic reticulum (ER) cholesterol and bile acid homeostasis (PubMed:20663892). Participates in sterol transport out of the ER and distribution into plasma membranes (PubMed:20663892). Ubiquitous. Highly expressed in lung. Mice show an increase in the abundance of type 1 oxidative muscle fibers in the diaphragm. Female mice show also an increase in the abundance of type 1 muscle fibers in the extensor digitorum longus. Conditional knockout in neurons leads to decreased body mass; male show reduced white adipose tissue mass while female show reduced perigonadal fat mass. Show also abnormal circling behavior and severe seizures. Belongs to the ARV1 family.