NR4A1 and myocardial infarction: In a mouse model of myocardial fibrosis after MI by distal left coronary artery ligation, Nur77 deficiency in mice showed exacerbated cardiac function and cardiac fibrosis after MI, with a concomitant increase in the expression of Col1a1 and FSP1, and a decreased expression of Pecam1 and Nos3 [13].