My research program focuses strongly on Major Histocompatibility Complex (MHC) receptors. These molecules are present on the surface of every cell in the body of vertebrates and are the key molecules which decide what belongs to the body and what is a pathogen. I was the first researcher to isolate an expressed MHC gene from fish, and produced the antibodies that allowed the first demonstration that they are present on the surface of fish cells. MHC receptors are highly polymorphic (that is they have many, many alleles present in a single population) and I continue to perform experiments to measure the evolution of MHC polymorphism in various fish population. We also work on the function of small proteins that pass signals between immune system cells to control immune responses: cytokines and chemokines.