IFN-γ Induces Hematopoietic Stem Cell Myelopoiesis through Meis1 in Tumor

• Tumor-derived IFN-γ induces a persistent myeloid-biased differentiation of hematopoietic stem cells (HSCs) in colorectal and lung cancer models. • Meis1 is identified as a critical transcription factor mediating IFN-γ-induced HSC myelopoiesis, and its ablation prevents myeloid differentiation. • HSC-derived myeloid-derived suppressor cells (MDSCs) suppress T cell function and promote tumor progression. • Combining anti-PD-1 with the anti-IFN-γ antibody Emapalumab inhibits HSC-derived MDSC production and enhances antitumor immunity, improving ICB efficacy.