cTn: When Heart Cells Cry for Help What is cTn? Cardiac Troponin (cTn) refers to a group of functional proteins located inside cardiomyocytes, where they play an essential role in maintaining heart contraction and pumping function. In clinical practice, cTn is further categorized into two cardiac-specific subtypes: cardiac troponin I (cTnI) and cardiac troponin T (cTnT). Both are unique to heart m...