PRNP and myositis disease: Our data show that: (i) myositis positively influences PrPSc accumulation in homogenized muscle tissue at preclinical time points and that a PrPC-expressing LRS is a prerequisite for this, (ii) PrPSc and prion infectivity are uncoupled in muscle with detectable PrPSc in the absence of prion infectivity at preclinical time points, (iii) muscle, unlike the LRS, has an intrinsically high ability to clear PrPSc once myositis has ceased, possibly involving autophagy.