Collagen type XIX is a FACIT (fibril-associated collagens with interrupted triple helix) collagen family member (Inoguchi et al. 1995) with a large non-collagenous N terminal domain that can self-assemble into higher order structures that are stabilized by intermolecular disulfide cross-links. Collagen type XIX is the least abundant collagen so far purified, comprising ?10-6% of dry weight in human umbilical cord (Myers et al. 2003). It is found in the basement membrane (BM) of normal human tissues. In developing embryos it is transiently expressed in certain muscular tissues and brain areas. Due to this localized expression, it is thought to be involved in the formation of specialized BM zones (Sumiyoshi et al. 2001). Collagen XIX is lost early in the development of invasive tumours, prior to penetration and eventual dissolution of the epithelial BM (Amenta et al. 2003). The NC1 domain of type XIX collagen exerts antitumor activity (Ramont et al. 2007).