CSF3 (colony stimulating factor 3) is a cytokine that primarily functions in hematopoiesis by controlling granulocyte production, differentiation, and activation 1. The protein promotes growth, proliferation, and survival of neutrophils and their precursors 1. CSF3 signals through its receptor CSF3R to activate downstream pathways including PI3K/Akt signaling 2. Beyond hematopoiesis, CSF3 plays pathological roles in multiple diseases. In acute lung injury and ARDS, CSF3 signaling represents a vital pathway in pulmonary inflammation 3. In chr17 rhinosinusitis without nasal polyps, CSF3 serves as a biomarker for the neutrophil-dominated Type 3 inflammatory endotype 4. CSF3 mediates triple-negative breast cancer progression by promoting glycolytic reprogramming through PGM2L1 2, and contributes to acute exacerbation of pulmonary fibrosis by disrupting alveolar epithelial barrier integrity via tight junction disruption 5. In idiopathic pulmonary fibrosis, CSF3 acts upstream of TGF-β in a positive feedback loop driving myofibroblast differentiation and excessive extracellular matrix deposition 6. Elevated CSF3 is also associated with specific long COVID symptoms including gastrointestinal dysfunction 7. These findings suggest CSF3 neutralization represents a potential therapeutic strategy across inflammatory and fibrotic diseases.