Leukocyte adhesion molecules promise to be highly effective as antigens in the antibody-directed leucocyte elimination treatment prior to grafting or in cases of acute and chronic inflammatory disease. This comprehensive review of contemporary research provides thorough discussions of the structure of these molecules, their in vitro function, and the role that they play in vivo as evidenced by results shown in inflammatory models where antibodies against these molecules are given to inhibit their function. The blend of basic science and clinical applications provides clear evidence of the biological relevance of cell-cell interactions and the many potential clinical dividends afforded by understanding the molecular basis of cell adhesion.