BETHESDA, Maryland — There are a number of rate-limiting steps, as the saying goes, that will affect the adoption of companion diagnostics (CDx), but FDA might not be the most conspicuous of these. Tamara Syrek Jensen, director of Medicare's coverage and evidence group (CAG) noted that the NIH genetic testing registry includes roughly 23,000 tests for about 4,000 diagnoses, and remarked, "I have no idea how I'm ever going to review" each of those tests as the related coverage requests come in.