In the past year, evaluation of cellular pathways of rheumatoid synovial fibroblasts has been the focus of several laboratories investigating the molecular and cellular mechanisms operating in the pathogenesis of rheumatoid arthritis. Major topics that have been reported on include the adhesion and interaction of synovial fibroblasts with cartilaginous matrix and other synovial cells, intracellular signaling, and activation of gene transcription. Novel approaches to inhibiting cartilage destruction have also been described. In the latter case, thorough multicenter characterization of the interleukin-1/interleukin-1 receptor antagonist pathways resulted in the first gene therapy trials in animals and humans.