"Next generation sequencing (NGS) has revolutionized molecular diagnostic testing. It is important to note that, as with many molecular diagnostic tests currently in clinical use, there are very few FDA-approved or FDA-cleared NGS assays, and thus analytical and clinical assay validation of laboratory-developed tests (LDTs) is essential to the application of NGS technology for clinical diagnostic testing. Both analytical and clinical performance parameters must be established for NGS-based LDTs. Analytical performance parameters include accuracy, precision, reportable range, and reference interval, as well as analytical sensitivity, analytical specificity, and any other parameter that is considered important to assure the analytical performance of a particular test (e.g., specimen stability, carryover). The clinical validity and clinical utility of the testing must also be considered. The College of American Pathologists (CAPs) Molecular Pathology Checklist requirements, universally recognized as providing best-in-class standards for clinical laboratory testing, address the analytical and clinical validation of NGS-based LDTs."