More than 20 different human proteins, intact or fragmented, proved their amyloidogenicity in vivo, among which we may count amyloid β (Aβ) peptide (in Alzheimer’s disease), α-synuclein (in Parkinson’s disease), islet amyloid polypeptide (in type II-diabetes), light chains of immunoglobulins, variants of human lysozyme [1,2], and transthyretin (TTR) [3]. Here, TTR is linked to Parkinson disease.