Funding Opportunity RFA-CA-13-019 from the NIH Guide for Grants and Contracts. The purpose of this Funding Opportunity Announcement (FOA) is to support innovative research projects designed to solve specific problems and paradoxes in cancer research identified by the NCI Provocative Questions initiative. These problems and paradoxes phrased as questions are not intended to represent the full range of NCI's priorities in cancer research. Rather, they are meant to challenge cancer researchers to think about and elucidate specific problems in key areas of cancer research that are deemed important but have not received sufficient attention.