Researchers in Trinity College have discovered a protein called mal which could open up new treatments for diseases like malaria, TB, pneumonia and MRSA.
Published today in the science journal Nature Genetics, scientists call this an important breakthrough.
Mal is a protein that can determine who gets a disease and how well they deal with it.
Acting as a switch, mal can turn on our immune system when a disease enters the body.
But there is also bad mal which can make some people twice as likely to contract an infectious disease. In the case of malaria, bad mal can increase the death rate by 500%.
