ABCB1 and hepatocellular carcinoma: High rates of FDG-6-phosphatase activity, high expression of P-glycoprotein, and low GLUT1 and GLUT2 expression in moderately and well-differentiated HCC [8] result in low uptake of FDG into the HCC cell, rapid phosphorylation of FDG, and then efflux of FDG back out of the cell.