ITGAM and atrial fibrillation: Whereas WT mice exposed to 14 days of Ang II infusion exhibited increased atrial fibrosis and concomitantly were noted for decreased threshold for atrial fibrillation, CD11b−/− mice not only displayed attenuated atrial PMN accumulation after Ang II treatment, but also less fibrosis, which translated into reduced susceptibility to atrial fibrillation.