Three days after Ad-FasL gene transfer into RA synovium in vivo, augmented FasL protein expression was observed (Fig. 3c), and an increased frequency of apoptotic cells in RA synovium was detected by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining (Fig. 3f). The gene discussed is FASLG; the disease is rheumatoid arthritis.