{{Short description|Protein found in humans}} {{Infobox gene}}
'''Collagen alpha-1(XXI) chain''' is a protein that in humans is encoded by the ''COL21A1'' gene.<ref name = "entrez">{{cite web | url = https://www.ncbi.nlm.nih.gov/gene?cmd=retrieve&dopt=default&rn=1&list_uids=81578 | title = COL21A1 collagen, type XXI, alpha 1 | work = Entrez Gene: COL21A1 | publisher = United States National Center for Biotechnology Information }}</ref> The protein is an extracellular matrix component of blood vessel walls, secreted by smooth-muscle cells. The protein may contribute to the extracellular matrix assembly of the vascular network during blood vessel formation.<ref>{{cite journal | vauthors = Chou MY, Li HC | title = Genomic organization and characterization of the human type XXI collagen (COL21A1) gene | journal = Genomics | volume = 79 | issue = 3 | pages = 395–401 | date = March 2002 | pmid = 11863369 | doi = 10.1006/geno.2002.6712 }}</ref>
== References == {{Reflist}}
{{Fibrous proteins}}
Category:Collagens
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