Monocarboxylate transporters (MCTs) are found ubiquitously expressed in many human tissues. The three main MCTs (MCT1, 2 and 4) have been especially well characterized in muscle and brain. Their function is to transport pyruvate and lactate in and out of the cell depending on concentration gradients. The aim of this study is to investigate the expression of MCTs in the epidermis of skin in vivo and in epidermal cells cultured in normal and hypoxic conditions to see if MCTs have a role in defining stem cell phenotype through influencing choice of metabolic pathway.