However, they did not find a significant relationship between FDG uptake and other factors such as tumor size, steroid receptor status, and expression of the glucose transporter protein GLUT-1, concluding that though some positive correlations were observed, the degree of metabolic changes after a malignant transformation was most likely explained by a number of complex interactions between the need for energy of malignant cells and their tumoral microenvironment showing some limitations of FDG-PET imaging. Here, SLC2A1 is linked to neoplasm.