164 Ann. N.Y. Acad. Sci. 961: 164–167 (2002). © 2002 New York Academy of Sciences. Molecular Signaling Breakout Session Summary Moderators CAROLINE DAMSKY, University of California, San Francisco MOHAMMAD HEIDARAN, BD Technologies Panelists DONALD BOTTARO, EntreMed, Inc. KATHRYN CROSSIN, Scripps Research Institute PATRICIA DUCY, Baylor College of Medicine DONALD INGBER, Harvard Medical School/Children’s HospitaL BROAD STATEMENT Tissues and organs consist of specialized living cells arrayed within a complex structural and functional framework generally known as the extracellular matrix (ECM). ECM composition and mechanics are important factors that contribute to the function and characteristics of each organ and tissue, such as the rigidity and tensile strength of bone, the resilience of cartilage, the flexibility and hydrostatic strength of blood vessels, and the elasticity of skin. Also important is the role of the ECM during growth, development, and wound repair, where it serves as a reservoir for sol- uble signaling molecules and, through its own dynamic composition and mechanics, a source of additional signals to migrating, proliferating, and differentiating cells. Artificial substitutes for the ECM, called scaffolds, consisting of natural and/or synthetic polymers, have been used successfully alone or in combination with cells and soluble factors to induce tissue formation and promote tissue repair. Cells are also central to many tissue engineering strategies, and significant efforts have been made to identify and propagate pluripotent stem cells, to identify signaling events important for proper differentiation, and to identify ideal microenvironments for maximum cellular function. These efforts have led to a convergence of research in bioengineering, biomaterials, ECM, cell growth and differentiation, and soluble factors that control cell fate. Recent developments in the multidisciplinary field of tissue engineering have provided a novel set of tissue replacement parts and implementation strategies. Sci- entific advances in biomaterials, stem cells, growth and differentiation factors, and biomimetic environments have created unique opportunities to fabricate tissues in the laboratory from combinations of engineered ECMs (scaffolds), cells, and biolog- ically active molecules.