Alpha-tocopherol (alpha-TOH) belongs to the fat-soluble vitamin E family and is the major form used by humans as an important antioxidant of plasma lipoproteins and cell membranes. It is secreted from the liver into the blood stream but as it is a lipophilic compound, it requires intracellular binding proteins to bind and transport it to exert its actions. One such protein is alpha-tocopherol transfer protein (TTPA, TPP1), a cytosolic protein highly expressed in liver and placenta (Arita et al. 1995, Kostner et al. 1995). The main function of TTPA is to maintain normal alpha-TOH concentrations in the plasma and extrahepatic tissues by binding to, and facilitating the transport of, alpha-TOH from lysosomes to the plasma membrane (Qian et al. 2005; reviews Kono & Arai 2015, Schmolz et al. 2016).