The goal of the U01 is to apply genome editors in organoid cultures to establish a predictive model for adverse events in human kidney cell types, including both acute and chronic disorders with life-threatening consequences. Genome editing platforms enable the efficient manipulation of specific DNA sequences in the human genome, and therefore have enormous potential as therapeutics. The studies proposed in this supplemental application bring together two complementary SCGE Consortium teams to advance combined in vitro and in vivo safety and efficiency testing for somatic cell genome editing. The in vitro component addresses human cells in our 3D organoid model, a rapid and high-throughput testing platform for preclinical assessments. However, the degree to which organoids can predict responses in vivo remains unclear thus this system will be integrated with the synergistic studies in the SCGE Testing Center to address topics of interest to regulatory agencies such as dose response, editing delivery components, safety, and potential toxicities to guide preclinical/clinical monitoring. As a prototype for proof-of-concept, studies focus on the kidney because ~20 million Americans suffer from chronic kidney disease. Kidney disease is on the rise particularly in children, a population that suffers disproportionately from genetic causes that could be targeted with genome editing. CRISPR/Cas9 editing delivered by adeno-associated virus (AAV) is proposed to introduce specific edits at the AAVS1 target locus. Collectively, these studies will establish a new regulatory paradigm which can be applied to a range of tissues and diseases.