Transport of solutes (e.g., ions, nutrients and metabolites) across the cellular membrane is a fundamentally important process for living cells to maintain their metabolic homeostasis. Active efflux is a mechanism responsible for moving toxic substances and antibiotics out of the cell; this is considered to be a vital part of xenobiotic metabolism. Multidrug efflux systems display the ability to transport a variety of structurally unrelated substrates from a cell and consequently are capable of conferring resistance to a diverse range of chemotherapeutic agents. The importance of efflux is now broadly recognized in clinical settings as it not only contributes to drug resistance in bacterial and mammalian cells, including cancer, but is also important in drug development efforts as it is a defining factor in drug distribution and elimination in tissues and organs. In addition to the efflux mechanisms, systems controlling the influx of solutes also contribute to multi-drug resistance and xenobiotic metabolism. New roles of influx and efflux in adaptation to various environments and signaling continue to emerge. Participants of the highly appreciated and productive past meetings on multi-drug efflux systems have made unprecedented progress in the understanding of fundamental mechanisms, diversity and functions of multi-drug efflux systems. The 6th meeting will focus on translating this fundamental knowledge into development of novel therapeutic, diagnostic and bioengineering tools. This conference will address both the efflux and influx systems, as the balance of these two counter flows defines and regulates substrate/drug accumulation in all cells and tissues. The conference will start with two keynote lectures provided by internationally recognized leaders in the field of membrane transporters. Following the keynote lectures, scientific sessions will be held to address the roles and biochemical mechanisms of drug transporters in normal physiology and pathology, in drug discovery and development as well as the emerging roles of drug transporters in stems cells, bioengineering and biofuel production. For the first time in the history of this meeting, this GRC (April 26 - May 1) will be held in conjunction with the Gordon Research Seminar (GRS) for young scientists (April 25 - 26). For additional information, please kindly visit the GRS web page.