Currently, cardiac troponins T (cTnT) and I (cTnI) are the best biomarkers for acute myocardial infarction (AMI) diagnostic.<h4>Case presentation</h4>Immune-mediated toxicity due to Pembrolizumab was suspected in a 70-year-old male patient with gastric adenocarcinoma. The gene discussed is TNNT2; the disease is myocardial infarction.