The same signal responsible for promoting the type of immune responses that cause asthma and allergy can also limit the type of inflammation associated with debilitating diseases like inflammatory bowel disease, arthritis and multiple sclerosis, according to researchers from the University of Pennsylvania School of Veterinary Medicine. The researchers discovered how IL-25, a signaling protein known as a cytokine, both prevents destructive inflammation and promotes immune responses associated with asthma and allergic responses.