This gene encodes a carrier protein responsible for the transport of thyroid hormones and retinol. The protein consists of a tetramer of identical subunits. Due to increased stability of the tetramer form of this encoded protein in mouse, compared to the human protein, this gene product has a reduced tendency to form amyloid fibrils. In humans, this protein binds beta-amyloid preventing its aggregation and providing a neuroprotective role in Alzheimer's disease. [provided by RefSeq, Mar 2010]