Ras-related protein Rab-3D, also known as GOV, is a member of the Ras superfamily of small Rab GTPases. Rab proteins play an important role for, either in endocytosis or in biosynthetic protein transport. Rab3D mRNA is predominantly expressed in white adipose tissue and, coincident with GLUT4, increases upon differentiation of 3T3-L1 broblasts into insulin-responsive adipocytes.