Chemokines are small proteins that direct the migration of white blood cells (including T cells) in the body. This process is very important in mounting an immune response against invading pathogens. Chemokine function is known to be implicated in autoimmune diseases such as multiple sclerosis and graft versus host disease, and has recently been linked to the ability of cancer to spread from one part of the body to others. Jennifer Cox is investigating the ability of a family of proteases to process and alter chemokine activity. Focusing on a group known as matrix metalloproteinases, she has uncovered that one of these proteases cleaves specific chemokines, altering their ability to induce the migration of T cells. Now, she hopes to use mouse models to prove that this interaction is relevant in the body. These studies will result in a better understanding of immune regulation at a molecular level and could have implications for the prevention of cancer spread and the treatment of autoimmune diseases.