In the past 25+ years my research interest has been the extracellular matrix and especially cell - basement membrane - interactions. The elucidation of the pathogenesis of osteoarthritis has also played a large role. Major contributions were to the molecular composition of basement membranes, as well as the discovery of chondrogenic progenitor cells (Cell Stem Cell, 2009) in late stages of osteoarthritis. Meanwhile, we have identified further chondrogenic progenitor cells in osteoarthritic human meniscus, cartilage from human rheumatoid arthritis and osteoarthritis of the TMJ in a mouse model. Currently, I am investigating the signal transduction pathways of these cells, to find cues to utilize them for cartilage regeneration.