However, it can be noticed that the mean incubation time observed at primary passage in tgOv rabbits (<200 days) is within the range of incubation time observed in sheep and transgenic mice expressing physiological levels of ovine PrP upon intracerebral infection, at the same dose, of fast scrapie prions ([23, 30]; 140 ± 5 days (6/6) in tg335 mice [23]). The gene discussed is PRNP; the disease is scrapie.