Macrophage plasticity and polarization are critical for immune responses and tissue homeostasis. Macrophages can adopt M1 (classical) or M2 (alternative) activation states in response to signals like IFNs, TLRs, or IL-4/IL-13. These states represent extremes of a continuum of activation states. Recent research has identified signaling pathways, transcriptional networks, and epigenetic mechanisms underlying M1-M2 polarization. Macrophages exhibit functional skewing under physiological and pathological conditions, such as ontogenesis, pregnancy, and disease. In some cases, macrophages can exist in multiple activation states, reflecting dynamic changes and complex tissue signals. Macrophages play essential roles in innate immunity, inflammation, and host defense. They also contribute to tissue remodeling and metabolic functions. Monocyte-macrophage lineage cells are diverse and plastic, responding to environmental cues to acquire distinct functional phenotypes. M1 macrophages are pro-inflammatory, while M2 macrophages are immunoregulatory and involved in tissue repair. The M1-M2 polarization is regulated by signaling pathways such as IRF/STAT, SOCS, and PPARs. Epigenetic changes and non-coding RNAs also influence macrophage polarization. In pathology, macrophage polarization is involved in inflammation resolution, tissue repair, infection, and cancer. M1 macrophages are involved in initiating and sustaining inflammation, while M2 macrophages are associated with resolution or chronic inflammation. In cancer, macrophages can be either anti-tumor or pro-tumor, depending on their polarization state. In obesity, macrophages in adipose tissue contribute to insulin resistance and metabolic disorders. Therapeutic strategies targeting macrophage polarization are being explored, including inhibitors of CSF-1, CCL2, and VEGF, as well as PPARγ agonists and statins. Understanding macrophage polarization is crucial for developing targeted therapies for diseases such as cancer, inflammation, and metabolic disorders. The plasticity of macrophages allows them to adapt to different environments, and their functional states are influenced by a complex interplay of signals. Further research is needed to fully understand the mechanisms underlying macrophage polarization and to develop effective therapeutic strategies.Macrophage plasticity and polarization are critical for immune responses and tissue homeostasis. Macrophages can adopt M1 (classical) or M2 (alternative) activation states in response to signals like IFNs, TLRs, or IL-4/IL-13. These states represent extremes of a continuum of activation states. Recent research has identified signaling pathways, transcriptional networks, and epigenetic mechanisms underlying M1-M2 polarization. Macrophages exhibit functional skewing under physiological and pathological conditions, such as ontogenesis, pregnancy, and disease. In some cases, macrophages can exist in multiple activation states, reflecting dynamic changes and complex tissue signals. Macrophages play essential roles in innate immunity, inflammation, and host defense. They also contribute to tissue remodeling and metabolic functions. Monocyte-macrophage lineage cells are diverse and plastic, responding to environmental cues to acquire distinct functional phenotypes. M1 macrophages are pro-inflammatory, while M2 macrophages are immunoregulatory and involved in tissue repair. The M1-M2 polarization is regulated by signaling pathways such as IRF/STAT, SOCS, and PPARs. Epigenetic changes and non-coding RNAs also influence macrophage polarization. In pathology, macrophage polarization is involved in inflammation resolution, tissue repair, infection, and cancer. M1 macrophages are involved in initiating and sustaining inflammation, while M2 macrophages are associated with resolution or chronic inflammation. In cancer, macrophages can be either anti-tumor or pro-tumor, depending on their polarization state. In obesity, macrophages in adipose tissue contribute to insulin resistance and metabolic disorders. Therapeutic strategies targeting macrophage polarization are being explored, including inhibitors of CSF-1, CCL2, and VEGF, as well as PPARγ agonists and statins. Understanding macrophage polarization is crucial for developing targeted therapies for diseases such as cancer, inflammation, and metabolic disorders. The plasticity of macrophages allows them to adapt to different environments, and their functional states are influenced by a complex interplay of signals. Further research is needed to fully understand the mechanisms underlying macrophage polarization and to develop effective therapeutic strategies.