CCN3 (cellular communication network factor 3) is a multifunctional secreted protein that serves as a critical regulator of stem cell homeostasis and tissue development. The protein acts as a brain-derived osteoanabolic hormone secreted from KISS1 neurons in the arcuate nucleus, particularly during lactation, where it maintains maternal bone health and offspring viability 1. CCN3 functions as an essential regulator of hematopoietic stem and progenitor cell function, acting through core signaling pathways including Notch and bone morphogenic protein to modulate self-renewal and maturation 2. The protein demonstrates context-dependent effects, typically functioning as a growth inhibitor in contrast to CCN2, with these proteins collaborating in a yin-yang fashion through mutual negative regulation systems closely associated with glycolysis 3. CCN3 plays protective roles in inflammatory diseases, as evidenced by its involvement in the Hippo-YAP signaling cascade where it regulates cellular senescence 4. In metabolic contexts, CCN3 correlates with fat mass and improves insulin sensitivity 5. Recent studies identify CCN3 as a potential biomarker for aortic dissection, where it appears downregulated and may have protective effects 6. Additionally, Mendelian randomization studies suggest CCN3 has causal associations with inflammatory bowel disease risk 7.