The Ras-related superfamily of guanine nucleotide binding proteins includes the R-Ras, Rap, Ral/Rec and Rho/Rab subfamilies, all of which are thought to play an important role in either endocytosis or in biosynthetic protein transport. The process of transporting newly synthesized proteins from the endoplasmic reticulum (ER) to various stacks of the Golgi complex and to secretory vesicles involves the movement of carrier vesicles and requires Rab protein function. Rab 35, also known as Rab 1C or RAY, is a 201 amino acid lipidanchored protein that is thought to function as a GTPase, playing a role in exocytotic and endocytotic pathways and functioning as an important factor in cytokinesis. Rab 35 is expressed ubiquitously and is encoded by a gene that maps to human chromosome 12, which houses over 1,100 genes and comprises approximately 4.5% of the human genome.