On April 4, 2019, the U.S. Food and Drug Administration's (FDA or the agency) Office of In Vitro Diagnostics and Radiological Health issued a Warning Letter to Inova Genomics Laboratory in one of the first FDA enforcement actions against a clinical laboratory for services offered as laboratory developed tests (LDTs) in more than five years, and certainly the first such action of which we are aware since FDA announced in late 2016 that it would not finalize the proposed framework and guidance documents for the regulation of LDTs.