Core Viewpoint - The study presents a novel CXCR4 partial agonist, TFF2-MSA, which enhances the efficacy of cancer immunotherapy by targeting immunosuppressive neutrophils and cancer-driven granulopoiesis, particularly in gastric cancer [2][3][8]. Group 1: Research Findings - TFF2-MSA is identified as a CXCR4 partial agonist that sensitizes gastric cancer mouse models to anti-PD-1 therapy [6]. - TFF2-MSA reduces immunosuppressive neutrophils and cancer-driven granulocyte production [6]. - The combination of TFF2-MSA with anti-PD-1 therapy induces a robust anti-tumor CD8+ T cell response [6]. - In gastric cancer patients, decreased levels of TFF2 are associated with an increase in polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) [6][5]. Group 2: Mechanism of Action - The study demonstrates that TFF2-MSA, when fused with mouse serum albumin (MSA), shows improved stability and effectively inhibits primary tumor growth and distal metastasis in gastric cancer mouse models [4]. - TFF2-MSA selectively reduces Hdc-GFP+ CXCR4high immunosuppressive neutrophils, enhancing the tumor-killing ability of CD8+ T cells mediated by anti-PD-1 [4]. - Unlike CXCR4 antagonists, TFF2-MSA also inhibits bone marrow granulocyte production, contributing to its therapeutic benefits [4]. Group 3: Implications for Cancer Therapy - The research proposes a new strategy that utilizes CXCR4 partial agonism to restore tumor sensitivity to immune checkpoint inhibitors [8].