ITGAM and cardiac arrest: Further analysis revealed that the number of cells undergoing pyroptosis and live cells expressing caspase-1 was predominantly increased in the CD45int CD11b+ population (Fig. 2e, f) but not in the CD45low CD11b+ population (Fig. 2g, h), indicating that the activated microglia population was the primary source of pyroptotic microglia and cells with elevated caspase-1 activity after cardiac arrest.