IL7R and COVID-19: This work also provides an extensive scaffold database as a general resource for alternative scaffold engineering and protein design projects, which recently resulted in the development of picomolar COVID-19 inhibitors22 and also served as starting scaffolds for a variety of newly designed binding proteins targeting FGFR2, TrkA, IL7Ra, and VirB8 for which co-crystal structures illustrate atomic accuracy of the overall folds23.