Glucose transporter 4 (GLUT4) is a multi-pass membrane protein. It is a member of the family of glucose transporters that facilitate glucose uptake by cells. GLUT4 is sequestered within cells not stimulated by insulin. After insulin stimulation, it is translocated to the cell surface where it transports glucose across the cell membrane. GLUT4 is found in skeletal and heart muscles and in adipose tissue. It is highly conserved between species.