COL8A1 encodes collagen type VIII alpha 1 chain, a non-fibrillar, short-chain network-forming collagen expressed throughout the vasculature and tumor microenvironment 1. Primary function involves extracellular matrix organization and structural support, with the C-terminal NC1 domain (vastatin) inhibiting endothelial cell proliferation and inducing apoptosis. COL8A1 functions as both a structural component and signaling molecule in matricellular communication 1. Mechanistically, secreted COL8A1 activates ITGB1 and DDR1 receptors on target cells, triggering PI3K/AKT and NF-κB signaling pathways 2. In cancer contexts, COL8A1 is specifically produced by myofibroblast cancer-associated fibroblasts (myCAFs) 3 and promotes tumor progression through epithelial-mesenchymal transition (EMT) and angiogenesis 4. COL8A1 expression is upregulated in multiple cancer types including colorectal 5, pancreatic 2, gastric 6, thyroid 7, and nasopharyngeal cancers 4, consistently correlating with poor prognosis and chemoresistance. Clinically, COL8A1 serves as a biomarker for cancer progression and fibrotic disease 8, with therapeutic potential through receptor antagonism or pathway inhibition to overcome drug resistance and metastasis.