Scientists believe they may have found a way to protect very premature babies against serious lung damage.
Some very premature babies have difficulty breathing
Babies who are born well before term can have difficulty breathing if their lungs are not fully developed.
They can sometimes struggle to take in enough air to keep them alive.
But oxygen ventilation can damage their fragile lungs, causing inflammation and disease.
This damage kicks the baby's immune system into action, sending an army of white blood cells into the lungs to repair the damage.
But in premature infants, these white cells often stay in the lungs too long causing even more damage.
Researchers at two universities in the United States believe they may have found a way to turn off this immune response and so protect babies' lungs.
They have shown that mice with high levels of a protein called superoxide dismutase are protected against this type of lung damage.
Researchers at Duke University Medical Center and the Medical College of Wisconsin believe targeting the gene that produces this protein could help premature babies.
"The key to stopping such inflammation in infant lungs might be superoxide dismutase," said Richard Auten, professor of paediatrics at Duke University Medical Center.
The researchers are now planning further studies to see if it is possible to control a baby's immune response safely.
"We want to understand how to modify this immune response in a safe way that prevents inflammation but avoids infections and allow normal lung development," said Professor Auten.
There is no good treatment to protect very premature babies against this type of lung damage.
At the moment, many are given steroids to help reduce the inflammation.
However, these drugs can slow brain and lung growth and affect their immune system.
A study by doctors in Belfast, published in April, found it can affect their mental ability.