[1] Fred Hutchinson Canc Res Ctr, Div Human Biol, Seattle, WA 98109 USA
[2] Fred Hutchinson Canc Res Ctr, Div Clin Res, Seattle, WA 98109 USA
[3] Cornell Univ, Coll Vet Med, James A Baker Inst Anim Hlth, Ctr Canine Genet & Reprod, Ithaca, NY 14853 USA