PRNP and Creutzfeldt Jacob disease: However, in contrast to PrP from non-CJD, PrP from fCJDIns had an additional set migrating at 31-33 kDa with pI 9.0-9.5 designated PrP 2D spots III’ (Fig. 7C), which fitted well with the full-length PrPIns molecule with 6 extra repeats in terms of their molecular weight.