Rationale Induction of apoptosis in fibroblast-like synoviocytes (FLS) has been proposed as a therapeutic approach. Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has been described as a pro-apoptotic factor on rheumatoid arthritis FLS (RAFLS) and suggested as a potential drug. We have previously shown that exposure to TRAIL induces apoptosis only in a portion of RAFLS. In the surviving cells, TRAIL induced …