Fellowships and Grant support

T.G.-P. was supported by postdoctoral fellowships from EMBO, CIHR and OIRM; U.B. was supported by an HFSP postdoctoral fellowship; J.R. was supported by an Ontario Graduate Scholarship, H.H. was supported by a Donnelly Centre Home Fellowship; A.J.B. was supported by a CIHR Postdoctoral Fellowship; M.A. was supported by an SNSF fellowship; B.R. and J.A.C were supported by NSERC studentships. This research was supported by grants from CIHR (A.-C.G., J.M. and B.J.B.), Canada First Research Excellence Fund (B.J.B.) and the Simons Foundation (B.J.B.). B.J.B. holds the Banbury Chair of Medical Research at the University of Toronto.