http://linkedlifedata.com/r... | skos:definition | "A collagen heterotrimer containing type IV alpha chains; [alpha1(IV)]2alpha2(IV) trimers are commonly observed, although more type IV alpha chains exist and may be present in type IV trimers; type IV collagen triple helices associate to form nets within basement membranes." [ISBN:0721639976] | lld:geneontology |