We also analysed prion infectivity levels in spleens collected 70 days after infection from control mice (Prnp+/-→Prnp+/- mice) and Prnpstop/-→CD21-Cre Prnpstop/- mice in which cellular PrPC was expressed only on FDC (Figure S2; n = 3/group). This evidence concerns the gene PRNP and infection.