Elevated plasma troponin level is useful in diagnosing myocardial damage because troponin subunits are unique to the heart muscle.
Troponin is a protein specifically located (i.e., specifically expressed) in the cardiac muscle cells.
Troponin is found in the plasma only when there is some type of cardiac damage, being, therefore, a biomarker.
A biomarker is a specific biomolecule that can be used in medicine for diagnostic purposes.
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