Both VP and hFasL-PA317 cells express full-length and short forms of hFasL. Western analyses were carried out by using anti-FasL antibody against the following preparations: FasL VP (lanes 2, 4, and 6); FasL-PA317 packaging cell line (lanes 1, 3, 5, and 7); the cKrox control VP (lane 9); the cKrox-PA317 packaging cell line (lane 8); and the starting PA317 packaging cell line (lane 10). Lanes 1–3 and 4–10 were independent experiments. Protein amounts loaded are indicated. The size of anti-FasL-reactive bands was estimated based on molecular mass standard. The 40-kDa band corresponded to the full-length FasL, and the 26-kDa band corresponded to sFasL (21).