PRNP and scrapie: Furthermore tga20 mice, which express 6–9 fold more PrPC in the central nervous system (CNS) than wt mice [46], [47], [48], succumbed significantly earlier to scrapie upon prion aerosol exposure for 10 min (20%) (tga20 mice: 134±4 dpi; CD1 mice: 202±12 dpi, p<0.0001; C57BL/6 mice: 185±11 dpi, p = 0.003; 129SvxC57BL/6 mice: 182±15 dpi, p = 0.003; Fig. 1B–E, Fig. S1, Table S1A and S1C).