The study identifies a reservoir of undifferentiated monocytes in the spleen, which are distinct from macrophages and dendritic cells (DCs). These monocytes are morphologically and functionally similar to those found in circulation. Upon ischemic myocardial injury, the spleen mobilizes these monocytes, increasing their motility and causing them to exit the spleen en masse. The mobilized monocytes accumulate in the injured tissue and participate in wound healing. This discovery highlights the spleen's role as a site for storing and rapidly deploying monocytes, providing a resource for the body to regulate inflammation. The findings also suggest that angiotensin II (Ang II) signaling promotes monocyte motility and tissue emigration from the spleen.The study identifies a reservoir of undifferentiated monocytes in the spleen, which are distinct from macrophages and dendritic cells (DCs). These monocytes are morphologically and functionally similar to those found in circulation. Upon ischemic myocardial injury, the spleen mobilizes these monocytes, increasing their motility and causing them to exit the spleen en masse. The mobilized monocytes accumulate in the injured tissue and participate in wound healing. This discovery highlights the spleen's role as a site for storing and rapidly deploying monocytes, providing a resource for the body to regulate inflammation. The findings also suggest that angiotensin II (Ang II) signaling promotes monocyte motility and tissue emigration from the spleen.