NIDDK has become the latest IC to pull out of the Parent R21:
http://www2.niddk.nih.gov/Funding/Grants/ApplicantGuidelines/R21.htm
Because other large ICs had pulled out of the Parent R21 FOA, apparently DDK was getting saddled with R21s that might otherwise have gone elsewhere. R21 programs in general have had an increased number of applications in recent years, likely due to the fact that many ICs have pulled out of the R03 program.
Which begs the question: If you are a researcher who is passed the point of a mentored K-award, how do you step up to the R01, whose reviewers seem to have a nearly insatiable appetite for preliminary data? Why are the small-format R-series grants at NIH drying up?