Patients with damaged organs could be helped by new treatments after scientists have discovered how tissues scar.
Researchers say that the finding could pave the way for new drugs and eventually reduce the number of patients on organ transplant waiting lists.
Fibrotic diseases occur in many tissues within the body - including the liver, lung or kidneys - and have a range of causes including viruses or toxins.
The development of new therapies to treat fibrosis and reduce the need for organ transplantation would potentially be a major step forward.
Experts say that the main source of scar tissue is found in specialised cells called myofibroblasts.
The study discovered that a molecule on these cells is a key regulator of fibrotic disease.
Scientists say that the molecule - called alpha v integrin - is a critical switch involved in turning on the myofibroblast cells to make scar tissue.
The team studied specially bred mice with fibrosis to see if removing the alpha v integrin molecule on myofibroblasts would reduce the amount of scar tissue in their organs.
Researchers found that when they removed alpha v integrin from these cells, the mice were protected from fibrosis of the liver, lung and kidneys.
They also found that when they treated the mice with a new experimental drug designed to block alpha v integrins, the animals were protected from liver and lung fibrosis.
When tissue scarring becomes severe, affected organs do not work properly and currently the only treatment for end-stage organ failure is transplantation. However the shortage of donor organs means that many patients die while waiting for surgery.