IL1R1 and myocardial infarction: Saxena et al., 2013 showed that IL1R1 signaling mediates early recruitment of Ly6Chi monocytes to the infarcted myocardium. Reperfused myocardial infarction had intense infiltration with Ly6Chi monocytes expressing IL1R1 that peaked after 24 hr of reperfusion (Saxena et al., 2013). Noteworthy, recent studies demonstrated that the failing human heart also contains HLA-DRneg/low monocytes (Bajpai et al., 2018).