Although these human and mammalian fatal neurodegenerative diseases (listed above) including bovine spongiform encephalopathies (BSE, also known as ‘Mad cow disease’) were reported to share many of the pathological aspect, however, the biggest thing in common is that they are all based on the major prion protein (PrP, encoded from PRNP gene but functionally not well defined yet) [18, 19]. Here, PRNP is linked to neurodegenerative disease.