Could function as an adhesive molecule and its matrix bound and soluble fragments may play a critical role in vascular biology. Forms homooligomers. Forms heterooligomers with SCUBE2. Forms heterooligomers with SCUBE3 (PubMed:33308444). Detected in endothelial cells. Highly expressed in platelets. Stored in platelet alpha granules, and transferred to the cell surface upon activation and aggregation. A smaller form, probably produced by limited proteolysis, after being released from the storage granules, is associated with thrombus and localized with the subendothelial matrices in atherosclerotic plaques. Down-regulated by inflammatory cytokines. N-glycosylated. Could be proteolytically cleaved to release a smaller active fragment.