For each challenge, CACHE will select a Challenge Lead who will be responsible for the coordination of experiments and logistics. The Challenge Lead will ensure best practices are used in challenge design, execution, and assessment, and codified in iteratively revised documents (such as living reviews or contributions to the NCATS Assay Guidance Manual). Challenge Leads will determine the details of specific challenges, and what compound properties -experimental or computed -beyond affinity for the target will be incorporated into the overall performance scores.