CX3CR1 and colitis: In animal models, Ly6C+ macrophages recruited from the bloodstream potentiate inflammation, suggesting that overactive responses may contribute to disease.3, 37 In contrast, tissue resident macrophage populations (CX3CR1+) integrate and secrete anti-inflammatory signals to prevent colitis and promote tissue repair and resolution.33, 38 Identifying subset-specific regulatory mechanisms in macrophage populations is a crucial step toward harnessing these populations therapeutically.