Lesion profiles of terminally scrapie-sick mice (tga20, CD1, C57BL/6 and 129SvxC57BL/6) infected i.c. or through aerosols were similar irrespectively of genetic background or PrPC expression levels (Fig. 2E and F), with CD1 and 129SvxC57BL/6 hippocampi and cerebella displaying only mild histological and immunohistochemical features of scrapie regardless of the route of inoculation. The gene discussed is PRNP; the disease is scrapie.