An ontogeny-cytokine code determines macrophage response polarity and tumor outcomes.

Tumor-associated macrophages can either promote or suppress cancer, but therapeutic targeting remains challenging because we lack a predictive framework for macrophage function. The prevailing M1/M2 paradigm oversimplifies how macrophage developmental origin (ontogeny) and local cytokines shape antitumor versus protumor behavior. We systematically map eight reference macrophage states by differentiating mouse bone marrow cells with M-CSF or GM-CSF and polarizing them with four key cytokines (IFN‑γ, IL‑4, IL‑10, TGF‑β). Using integrated transcriptomic profiling, 3D tumor spheroids, and experimental metastasis models, we find that macrophage ontogeny determines whether cytokines promote or suppress tumor progression. Most notably, IL-4 induces opposite effects depending on ontogeny: promoting tumor growth, invasion, and metastasis in M-CSF-derived macrophages, while suppressing these processes in GM-CSF-derived macrophages. A similar ontogeny-dependent divergence was observed for IL-10, whereas IFN-γ consistently exerted antitumor effects and TGF-β protumor effects across both lineages. These findings define an ontogeny‑cytokine interaction framework that determines macrophage function based on developmental origin and cytokine context. By identifying ontogeny as a key determinant of cytokine responses, this work provides a conceptual basis for more precise macrophage-directed cancer immunotherapy strategies.