Just a few days ago the news came out of the death of a little girl from an allergic reaction to a simple ice cream. Unfortunately, allergies, especially food allergies, are increasing in number and often the cure is not so simple. Examples of this are intolerances and pathologies such as celiac disease. Scientists at the Garvan Institute of Medical Research in Sydney have discovered what is behind the most serious allergic reactions , what can be life threatening. It is the combination of two molecules of the immune system , IL-4 and IL-21. Biologist Stuart Tangye writes in the scientific journal Blood : "When the two molecules combine, the allergic reaction is much more powerful, and we now know that any allergy treatment will do best by neutralizing one or both molecules. The results, obtained currently in the lab, they are encouraging in an age where the frequency of allergies continues to rise."