The authors of this article are all employees and stockholders of Eli Lilly and Company, which supported this research, and have no financial ties or connection to any company or party supplying equipment or reagents used in the experiments conducted. T Umberger, W Ming and R Siegel are coinventors of a pending patent application. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.