SPP1 and heart failure: These broad categories further differentiate into context-dependent subpopulations (Table 5): for example, TREM2hi foam cells in atherosclerotic plaques facilitate lipid uptake and enhance cholesterol efflux; post-MI TREM2hi macrophages upregulate Arg1 and IL-10 to promote reparative processes; SPP1+ macrophages secrete TGF-β and IL-10, exacerbating fibrosis; and CD72hi subsets amplify inflammatory signaling, accelerating heart failure progression.