Scientists identified p21⁺Trem2⁺ senescent macrophages as major culprits behind inflammaging—the chronic inflammation that accelerates aging. These dysfunctional immune cells accumulate in aging liver tissue and fatty liver disease, secreting inflammatory signals driven partly by mitochondrial DNA leaking into cell cytoplasm and triggering interferon responses. Crucially, senolytic drugs targeting these senescent macrophages reduced liver inflammation and fat accumulation in both aged mice and those with metabolic liver disease. This discovery fundamentally reframes our understanding of inflammaging by pinpointing a specific immune cell type rather than generic "senescent cells." The liver focus is particularly relevant given its central metabolic role and vulnerability to age-related dysfunction. While promising, the research remains largely in mouse models, and human validation is limited to tissue analysis. The therapeutic implications are substantial—existing senolytics might be repurposed to target this newly identified cellular driver of aging. However, selectively eliminating senescent macrophages without compromising normal immune function presents a complex challenge that will require sophisticated drug development approaches.