Midges are those tiny biting flies that are the bane of the equine existence. Some horses don’t seem to have any allergic effects, but others are absolutely miserable from them. Researchers at the University of Edinburgh have found that all horses react – just in different ways. Those horses that do not seem to have any effect are in fact reacting – but their reaction is by a cytokine that actually blocks the allergic response. This finding could lead to ways of helping a body know which cytokine path to take that will prevent the allergic response.