The Rab27A gene encodes a protein that belongs to small GTPase superfamily known as Ras-related protein Rab-27A. The encoded protein is membrane-bound and is involved in protein transport. The role of this protein seems critical in pigment-producing cells called melanocytes and in certain immune system cells. Mutations in Rab27A cause Griscelli syndrome type 2. Alternative splicing is known to occur at this locus and four transcript variants have been identified.