Dr. Martel is a full professor of Medicine at Porto University. She has been working on the transport of organic compounds (organic cations, folate, thiamine, glucose, serotonin, butyrate, MPP+)across cell membrane. Most of her work has been conducted at the intestinal and placental level, but transport at other epithelia (blood-brain barrier, liver) have also been performed. More recently, transport in cancer cells is also being studied. Her current research focuses on potential interaction of drugs and food components with the transport of organic compounds, on the effect of some particular pathologies on the transport characteristics, and on the relation between transport of a substance and its biological activity.