The elimination of synoviocytes from RA synovium after multiple applications of FasL gene transfer results in a significant reduction in RA synovium size and weight in vivo in the RA-SCID mice (Fig. 5; Table 1) along with dramatic synovial cell death detected by TUNEL staining (Figs 3g–I and 4). This evidence concerns the gene FASLG and rheumatoid arthritis.