Monitoring cardiac troponin Ⅰ(cTnI)or T(cTnT)for the detection of myocardial injury and for risk stratification in acute coronary syndromes(ACS)has been endorsed by the laboratory medicine community(IFCC,AACC,NACB)and the cardiology community(ESC and ACC).The clinical laboratories has long been argued on the best cut-point values for troponin assay-some believe it should be set at the 99~(th)percentile of the reference population,while others believe it should be at the level where the particular assay's coefficient of variation(CV)is less than 10%,with the 10% CV varying by test manufacturer.Besides,there are numerous cTnI measurement systems,confusion regarding cTnI measurements has resulted large variability demonstrated among the cTnI assays.The aim of this opinion is to reflect on some concepts related to using cTn in clinical practice.