PRNP and prion disease: From the neuropathological standpoint, one of the consequences of the prion hypothesis proposed by S. Prusiner (who received the second Nobel Prize for TSE in 1997) was the possibility to raise specific anti-PrP antibodies as tools for the detection of prions by immunohistochemistry (in fixed brain tissue) and by immunoblot (in frozen brain tissue), allowing the definite diagnosis of prion diseases based on the molecular alteration of PrPSc, rather than merely on the morphological changes of cerebral tissue [73].