Markers / Targets — The specific substances, genes, proteins, hormones, or biological indicators that a lab test is designed to detect or measure in a patient sample. Markers and targets define what the test is actually looking for — for example, TSH is a marker for thyroid function, and PSA is a marker for prostate health. The terms are often used interchangeably, though in some contexts target is used more specifically in molecular or genetic testing to refer to a precise sequence or biomarker being detected.
See also: Compendium, IFU, Wet Lab