Of the U.S. biobanks, almost half (43%-49%, tabulated for the two categories of U.S. biobanks) addressed issues related to the return of IFs and IRRs in some way. However, that means that more than half did not. Given how little literature exists offering guidance to biobanks on IFs and IRRs, it is not surprising that we found that many biobanks did not address return of IFs and IRRs.