Cartilage has two general roles: On the one hand, cartilage is a permanent tissue of outstanding biomechanical properties in the adult organism, providing joints with elasticity and high mechanical stability and ensuring mobility. On the other hand, cartilage has evolved in evolution as a transient tissue, shaping a model of the skeleton. Osteoarthritis (OA) and other degenerative joint diseases are not an inevitable fate coming with age. Several decades of research have shown ample evidence for genetic predisposition and for environmental or occupational risk for developing osteoarthritis. Nevertheless, there is still insufficient progress in understanding the pathogenesis of OA, including mechanisms of cartilage destruction and joint remodeling. As a result, there has only been slow progress in the development of medication for prevention, therapy and diagnosis of OA in early phases, leaving joint replacement operations as the final therapy in late stages. With the recognition that degeneration and remodeling events in OA cartilage reflect changes in differentiation, gene expression and metabolic activities of the articular chondrocyte, the biology of this cell type has been moving to the center of research focus. Major progress in our understanding problems of cartilage degeneration, hypertrophy and remodeling in osteoarthritic joints has come from basic studies using tissue culture and transgenic animals. Strong evidence shows that the molecular mechanisms responsible for these events are very similar to mechanisms regulating chondrocyte differentiation, maturation and endochondral ossification in skeletal development This overlap of regulatory phenomena was a major rationale for the first two Gordon Conferences on cartilage biology. These two very successful conferences on cartilage biology brought together, for the first time, the fields of skeletal development, biochemistry, biomechanics, cell- and molecular biology of cartilage with the fields of cartilage pathology, human genetics of skeletal disorders, orthopedic research and tissue engineering.