Elastin is a fibrous protein found in various tissues of the body, such as the lungs, arteries, skin, and ligaments. Its primary function is to provide elasticity and flexibility to these tissues, allowing them to stretch and return to their original shape. It is crucial in forming the extracellular matrix and plays an essential role in the ability of organs and tissues to expand and contract without losing their structure.

Biologically, elastin is synthesized from a precursor called tropoelastin, which then organizes to form elastic fibers. As we age, the amount and functionality of elastin in the body decrease, contributing to the appearance of wrinkles in the skin and the loss of elasticity in blood vessels and other organs.