TREM2 and myocardial infarction: Specific knockout of TREM2 in macrophages led to a significant decrease in heart function as EF (23 ± 2.46% versus 10.95 ± 0.63%, P < 0.001) and fractional shortening (FS) (10.51 ± 1.20% versus 4.86 ± 0.28%, P < 0.001), combined with an increase in LVEDV (LV end-diastolic volume), LVESV (LV end-systolic volume), and so on compared to the control group following MI (Fig. 2A, B and Supplementary Fig. 4E).