NLRP3 inflammasome has been shown to be activated in MI mice 23, 24 and knockdown of its expression can reduce infarct size and improve myocardial function.23, 25 Besides, NLRP3 inflammasome has been proved to be activated predominantly in macrophages.26, 27 Studies showed that ROS derived from NADPH oxidase and mitochondria are involved in NLRP3 inflammasome activation, and inhibition of ROS prevents the activation of NLRP3 inflammasome.35, 36 However, the exact mechanism is not clear. Here, FMO5 is linked to myocardial infarction.