1. From the Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada (S.F., J.T., K.A.); Molecular Structure and Function Program, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada (S.F., C.B., M.N., J.T., K.A.); and Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY (J.I., M.H.).