Collagen is a protein that strengthens and supports many tissues in the body, including cartilage, bone, tendon, skin and the white part of the eye (sclera).

The COL1A1 gene produces a component of type I collagen, called the pro-alpha1(I) chain.

These triple-stranded, rope-like procollagen molecules must be processed by enzymes outside the cell.

Once these molecules are processed, they arrange themselves into long, thin fibrils that cross-link to one another in the spaces around cells.

The cross-links result in the formation of very strong mature type I collagen fibers.