Purified by immunoaffinity chromatography. Collagen III is a fibrillar collagen that is found in extensible connective tissues such as skin, lung, and the vascular system, frequently in association with type I Collagen. Mutations in the gene are associated with Ehlers Danlos syndrome type IV, and with aortic and arterial aneurysms. Although alternate transcripts have been detected for this gene, they are the result of mutations; these mutations alter splicing, often leading to the exclusion of multiple exons. Source: Collagen Type III, from human placenta.