NRG1 and infarction: Our study identified 2 complementary pathways activated by RIPC-mediated Nrg1 secretion: (1) ErbB2/4-cSrc-NO axis and (2) ErbB2/4-ATG5-Trx2 axis that converge to protect myocardial perfusion and infarction in I/R (Figure VIII in the Data Supplement).