R. K. C. is a consultant for Regeneron and Optinose. J. H. T. has received grant support from the NIH/National Institute of Allergy and Infectious Diseases (NIAID) and NIH/National Institute on Aging (NIA) and has served as a consultant for Regeneron, GlaxoSmithKlline, and AstraZeneca. N. I. C. is supported by the NIH/National Cancer Institute and the Burroughs Wellcome Fund. The remaining authors declare that they have no relevant conflicts of interest.