This gene encodes a protein that is involved in endoplasmic reticulum-to-Golgi trafficking and regulation of cholesterol metabolism. Three major classes of transcripts are generated from this gene- melanoma inhibitory activity 2-specific transcripts, cTAGE family member 5-specific transcripts and transcripts that include exons from both these transcript species. Additionally, alternative splicing in these transcripts results in multiple transcript variants encoding diverse isoforms. A mutation in this gene (couch-potato or cpto) may result in low levels of plasma cholesterol and triglycerides. [provided by RefSeq, Sep 2016]