The cellular prion protein (PrPc) is a protein found on the cell surface of many cell subtypes, especially neurons, anchored by a glycosyl-phosphatidylinositol residue. The physiological role of PrPc is still not understood. However, it is known that participates in copper uptake, protection against oxidative stress, cell adhesion, differentiation, signalling and cell survival. Moreover, it is also involved in memory formation. Despite the numerous functions given to PrPc, its discovery did not occur due to its altered isoform involvement (PrPsc) as an infectious agent of spongiform encephalopathies These diseases are unique because they can be hereditary, sporadic or have an acquired etiology. Much has been done concerning this intriguing protein, but there is still the need for more studies to truly understand PrPc functions and PrPsc pathogenesis mechanisms. In this way, new and more effective therapeutichal approaches can be developed, and more information on other amyloid diseases can be gathered.