In order to evaluate the role of Cys73 of Trx1 in mediating transnitrosylation of cardiac proteins during myocardial ischemia, we conducted proteomics analyses using tandem mass tag (TMT) labeling of S-nitrosylated proteins in WT and Trx1-C73S–KI mice. The gene discussed is TXN; the disease is myocardial ischemia.