MSMB and Cachexia: While the transgenic mouse model overexpressing human PrP was unable to propagate either brain-derived or misfolded rec-PrPs inocula (at least by the first passage), Tga20 mice succumbed showing principally lethargy and progressive cachexia at 506 ± 30 dpi and 297 ± 37, respectively (Table 1), with a duration of the disease of 2–3 weeks, similar in both groups.