From the Departments of Medicine (M.L.G., C.S.W.), Molecular Biology and Biochemistry (M.L.G.), and Physiology and Functional Genomics (C.S.W.), University of Florida, North Florida–South Georgia Veterans Health System (C.S.W.), and Malcom Randall Veterans Affairs (VA) Medical Center (C.S.W.) — all in Gainesville, FL; and the Department of Physiology and Membrane Biology, University of California School of Medicine at Davis, Davis (L.R.).