Lungs are still developing when a premature baby is born. If the lungs are damaged by O2 and ventilators, the Type I cells that are supposed to line the developing alveoli may produce too much free RAGE, a protein normally on the surface of the Type I cell. This RAGE will adhere to the growing lung scaffold or matrix at sites where the Type I cells are supposed to attach. This prevents the Type I cells from developing normally and can lead to chronic lung damage or bronchopulmonary dysplasia.