definiens: or means : ( a ) in the United States, an Assay intended for use in disease identification, monitoring, prognosis or treatment selection, including a determination of the state of health, in order to cure, mitigate, treat or prevent disease or its sequelae, as more fully defined in 21 C.F.R. § 800 et seq ., including so -called complementary diagnostics ( e.g., those used to identify patients whose Biomarker status is associated with a changed therapeutic response ) and companion diagnostics for a pharmaceutical product as defined in FDA ’s “ Draft Guidance for Industry and Food and Drug Administration Staff - In Vitro Companion Diagnostic Devices ”, ( b ) in the Eu ropean Union, an in vitro diagnostic medical device as defined in the European directive 98/79 / EC, and ( c ) any similar definitions set by Regulatory Authorities in Markets outside of the United States and the European Union or as may be updated by Regulato ry Authorities in the United States and the European Union in the future