A 4-week continuous intracerebroventricular infusion (150 μg/day) of HPMC samples when given 3 days post-infection (dpi) demonstrated remarkable extension of survival times in Tg7 mice expressing hamster prion protein (PrP) [13–15] intracerebrally infected with the hamster-adapted 263K prion [16]. This evidence concerns the gene PRNP and infection.