Alternative sequence (6); Beta strand (17); Chain (1); Disulfide bond (6); Domain (6); Glycosylation (9); Helix (2); Lipidation (1); Modified residue (4); Motif (2); Mutagenesis (11); Natural variant (5); Region (2); Sequence conflict (6); Signal peptide (1); Topological domain (2); Transmembrane (1); Turn (1); Expressed on platelets and leukocytes and is primarily concentrated at the borders between endothelial cells (PubMed:18388311, PubMed:21464369). Expressed in human umbilical vein endothelial cells (HUVECs) (at protein level) (PubMed:19342684, PubMed:17580308). Expressed on neutrophils (at protein level) (PubMed:17580308). Isoform Long predominates in all tissues examined (PubMed:12433657). Isoform Delta12 is detected only in trachea (PubMed:12433657). Isoform Delta14-15 is only detected in lung (PubMed:12433657). Isoform Delta14 is detected in all tissues examined with the strongest expression in heart (PubMed:12433657). Isoform Delta15 is expressed in brain, testis, ovary, cell surface of platelets, human umbilical vein endothelial cells (HUVECs), Jurkat T-cell leukemia, human erythroleukemia (HEL) and U-937 histiocytic lymphoma cell lines (at protein level) (PubMed:12433657, PubMed:18388311). {ECO:0000269|PubMed:12433657, ECO:0000269|PubMed:17580308, ECO:0000269|PubMed:18388311, ECO:0000269|PubMed:19342684, ECO:0000269|PubMed:21464369}.