PRNP and Creutzfeldt Jacob disease: Interestingly, PET-blot examination performed using Thermolysin digested PrPC completely from the frontal cortex brain tissue of a non-CJD control case, while in the present cases the worm-like structures remained visible, and in the cortex of a subject with CJD abundant PrPSc deposition was seen (Figure 1m-o).