OBJECTIVES/GOALS: NCATS requires that CTSA-funded pilot projects focus on translational science (TS) and evaluate the translational process. However, a consistent understanding of TS remains elusive. This gap is being addressed by a consortium of 12 CTSA hubs aimed at identifying distinctive features of TS and translational research (TR) proposals. METHODS/STUDY POPULATION: CTSA External Review Exchange Consortium (CEREC) is a reciprocal review collaboration among CTSA hubs. Reviewers were CEREC members from hubs that submitted CTSA applications (PAR-21-293); read the Notice of Funding Opportunity (NOFO) Clinical and Translations Science Pilot Module; and discussed TS with their hubs “a fair amount” or “quite a bit” and then they independently categorized proposals. Proposals were labeled TS or TR if reviewers reached a consensus on category assignment; without consensus, proposals were labeled unclassified. In addition to category assignment, reviewers commented about their classifications. R was used to evaluate the comments and create word clouds with phrases/themes that distinguished between the categories of proposals. RESULTS/ANTICIPATED RESULTS: Twelve CEREC participating hubs submitted 26 proposals, which were funded prior to the new NCATS TS requirements. Eight reviewers from distinct CEREC hubs evaluated and classified each proposal as TS or TR. Consensus (at least 87% agreement) was reached for 12 proposals, 6 TS and 6 TR. Reviewers provided comments describing the rationale for their classifications for 70% of the proposals. Qualitative analysis of the reviewers’ comments and rationale by classification (TS, TR, or unclassified) revealed common themes within and differences between groups and shed light on what defines TS and TR. The most frequent themes that distinguished TS from TR were generalizability across multiple diseases and a focus on increasing research efficiency. DISCUSSION/SIGNIFICANCE: NIH is focused on research that meets the new definition of TS. Investigators seeking to address this funding priority should explicitly state the relevance of their research to multiple diseases and to the acceleration of future research. Programs seeking to attract TS projects should instruct applicants to include this information.