SNCA and synucleinopathy: It has been shown that IAPP can accelerate α-synuclein amyloid formation in vitro (Horvath and Wittung-Stafshede, 2016) and the interaction between IAPP and α-synuclein in the pancreatic β cells of the patients with synucleinopathies has been detected (Martinez-Valbuena et al., 2018).