PTGS2 and neoplasm: Therefore, many studies have focused on defining the relationship between FDG uptake and the expression of tumor biomarkers, including nuclear- associated antigen Ki-67, cyclooxygenase-2 (Cox-2), vascular endothelial growth factor (VEGF) and the glucose transporter 1 (GLUT1) in relation to lung cancer [4], [8], [9].