) Research on fibronectin and integrins has expanded greatly in the last 10-20 years. These molecules control many basic biological functions such as cell adhesion, determination of cell shape and differentiation, organ and tissue development, hematopoiesis, immune cell function, tumorigenicity and metastasis, cell migration, cytoskeletal organization, and organization of the extracellular matrix. More recently, it has become obvious that integrins collaborate with growth factors to regulate cell proliferation and apoptosis, and thus have a major involvement in cell signaling. In addition, several of the integrins, including Alpha-2b-beta-3 on platelets, alpha-5-beta-3 on tumor blood vessels, and alpha-4 integrins on immune cells, have become widely recognized as targets for therapeutic intervention. The overall importance of fibronectin and integrins is further emphasized by the results from several knockout mouse experiments. In many cases, null/null mutations have produced embryonic lethal or perinatal lethal phenotypes. The challenge for the cell adhesion field over the next several years will be to comprehend and organize the large amount of new structural information and design experiments based upon it; learn the relative biological importance of the several seemingly redundant adhesion systems; and apply the new insights to the treatment of human diseases. The 1997 Gordon Research Conference on """"""""Fibronectin, Integrins, and Related Macromolecules"""""""" will serve as a valuable forum to present and discuss new information, identify problem areas, and plan new approaches.