TTR and amyloidosis: The pivotal role of amyloid oligomers as the main culprits of cytotoxicity has been also demonstrated for several amyloid disease-related proteins, such as α-synuclein in PD, β2-microglobulin in dialysis-related amyloidosis, transthyretin in familial amyloid polyneuropathies, amylin in type II diabetes and others [38–40].