PRNP and prion disease: Across doses of 0 (saline), 30, 100, 300 or 500 μg of active ASO 1, Prnp RNA reduction tracked with incubation time in animals that ultimately succumbed to prion disease (Figure 3B), with a significant increase in time to symptomatic endpoint even at 21% knockdown (median 173 versus 152 dpi at 30 μg, P = 0.002, two-sided log-rank test).