Rabbit G-CSF (Granulocyte Colony-Stimulating Factor, CSF3) is a hematopoietic cytokine belonging to the colony-stimulating factor family, which also includes GM-CSF (CSF2) and M-CSF (CSF1) that regulate the development and function of myeloid immune cells. In rabbits (Oryctolagus cuniculus), G-CSF is produced by macrophages, endothelial cells, fibroblasts, and other stromal cells in response to infection, inflammatory cytokines, or tissue injury. Rabbit G-CSF binds to the G-CSF receptor (CSF3R) expressed on myeloid progenitor cells in the bone marrow, activating intracellular signaling pathways such as JAK/STAT, MAPK/ERK, and PI3K–AKT, which promote the proliferation, differentiation, and survival of granulocytic precursor cells, particularly neutrophils. In rabbit immunity, G-CSF plays an important role in innate immune defense by regulating neutrophil production and mobilization during bacterial infection or inflammatory responses. Rabbits are also used as animal models for studying neutrophil biology and inflammatory disease, and G-CSF has been investigated in rabbit models of bacterial pneumonia, where stimulation of granulopoiesis enhances neutrophil recruitment to the lungs and improves bacterial clearance, providing insights into host defense mechanisms and therapeutic strategies for infectious diseases.