On Feb. 4, 2017, NCATS hosted another Assay Guidance Workshop for High-Throughput Screening and Lead Discovery. The session took place at the Society for Laboratory Automation and Screening’s annual international conference, held this year in Washington, D.C. More than 30 industry and academic researchers from nine countries and 12 U.S. states participated in the workshop, and nine Assay Guidance Manual editors covered a range of concepts critical for pre-clinical drug discovery. Open discussion featured topics including reproducible and robust methodologies, reagent validation, and statistical concepts for data analysis and assay interpretation. Plans for the next workshop are underway.