1. From the Department of Laboratory Medicine (E.S., W.L., J.-M.W., Y.Y., N.Q., T.W.K.), University of California, San Francisco; Institute of Biology and Medical Genetics (V.K., M.P.), 1st Medical Faculty, Charles University, Prague, Czech Republic; and Institute of Physiology (V.K., M.P.) and Czech Academy of Sciences, Prague, Czech Republic.