Sharks are well known for their incredible resistance to disease. The exact reason for this resistance has always been a bit of a mystery. While performing research as a graduate student almost thirty years ago, John Marchalonis took several milliliters of blood from the heart of a shark. Marchalonis discovered two proteins, one large and one small, which could link together to form a Y-shaped structure. This Y-shaped structure, which consisted of the two proteins, had the ability to stick tightly to chemicals that did not belong inside the shark. This was an immune system response that would destroy the foreign invaders. This finding showed that sharks have disease-fighting antibodies that are similar to those found in humans….