SLC2A1 and neoplasm: In addition, tumors obtain more glucose by upregulating the high-affinity glucose transporter protein GLUT1, downregulating transporter proteins with low affinity, consuming large amounts of glucose, converting large amounts of glucose-derived pyruvate to lactate through lactate dehydrogenase (LDHA) activity, and facilitating the transfer of lactate from tumor cells to the extracellular compartment by monocarboxylic acid transporter proteins (MCTs), even in oxygen-rich environments [12,13,14].