Rosen was awarded $2.2 million for the initial five year period. The award is renewable for an additional five years, for a potential total funding of $4.4 million. The MERIT Award will be used to further Rosen’s research into the mechanisms of cellular uptake and detoxification of the poisonous heavy metal arsenic.  The project, which is in its 22nd year, has elucidated the way in which arsenic is taken into cells, and the ways that cells protect themselves from this toxic metal.  Nearly a decade ago, Rosen identified the transport protein that brings arsenic into bacterial cells. These proteins, called aquaporins, are also responsible for uptake of water and other nutrients into cells.  Importantly, some drugs that are used to treat leukemia or infectious diseases contain arsenic or a related metal, antimony.  Rosen and his collaborators have shown that these drugs are also transported by aquaporins, which has proven to be of importance in understanding their mechanism of action. Rosen has since extended these studies to demonstrate that aquaporins bring arsenic into most organisms, from bacteria to humans. In addition, his laboratory has identified the transport systems that remove arsenic from cells as a way of detoxification.