Troponin I (TnI) is the inhibitory subunit of troponin, the structural protein involved in the regulation of striated muscle contraction.TnI is the inhibitory subunit; blocking actin-myosin interactions and thereby mediating striated muscle relaxation. Cardiac Troponin I (cTnI) is produced by cardiac muscle. cTnI has been considered as one of the most specific and sensitive markers of myocardial damage like acute myocardial infarction (AMI) for decades.
