White blood cells are the key elements of the immune system that keep our bodies healthy. Normally these cells circulate in the bloodstream, but upon infection or injury, the cells exit from blood vessels and enter the damaged tissue to promote healing. Proteins on the cell surface, called cell adhesion molecules, take white blood cells to the afflicted site. These molecules are tightly regulated to ensure they only allow cell migration into damaged tissues. When regulation fails, cell adhesion molecules may promote inflammatory diseases such as arthritis, inflammatory bowel disease and atherosclerosis or metastasis (transfer from one organ or body part to another) of cancer. Kelly Brown is studying CD44, a cell adhesion molecule found in mice and humans on virtually all cell types. Kelly is investigating CD44 on particular white blood cells called monocytes. Once in damaged tissues, these cells eliminate pathogens and alert the rest of the immune system. She is examining the changes that occur in CD44 when monocytes are activated and how the regulation of CD44 contributes to monocyte function during an inflammatory response. Kelly ultimately hopes to learn how to block or promote CD44, which could lead to new treatments for inflammatory diseases and cancer.