The immune system must strike a balance between fighting off illness and infection and damaging tissues in the body. If the balance swings too far in either direction, the results can be disastrous. Over-stimulation of the immune system can result in tissue damage, low blood pressure, organ failure and death. A good example is toxic shock syndrome, which occurs when an enormous overreaction by the immune system triggers a rapid drop in blood pressure, leading to multiple organ failure. Mortality is as high as 30 to 40 per cent Researchers recently suggested that this type of reaction may explain, in part, why the 1918 flu epidemic was so deadly. A protein called LL-37 is involved in healing wounds and growing new blood vessels, a process that is vital for repairing damaged tissue. Niall Filewod is investigating whether or not LL-37 can help calm an activated immune system. Thus diminishing the effect of excessive immune responses and protecting the body from toxic shock. If so, this research could lead to new drugs to treat conditions ranging from sepsis to arthritis that result from immune system reactions gone awry.