1 Department of Human Genetics, University of Chicago, Chicago, Ill. Electronic address: cober@uchicago.edu.
2 Department of Public Health Sciences, Center for Allergy, Asthma and Immunology Research, Henry Ford Health System, Detroit, Mich. Electronic address: CJOSEPH1@hfhs.org.
3 Department of Human Genetics, University of Chicago, Chicago, Ill; Department of Ecology and Evolution, University of Chicago, Chicago, Ill. Electronic address: jnovembre@uchicago.edu.