P4HB and neurodegenerative disease: PDI family members have been reported to prevent abnormal aggregation of several proteins/peptides associated with neurodegenerative diseases through a direct interaction between PDI and these amyloidogenic proteins, including prion proteins [60], [61], α-synuclein [62], amyloid β peptides [63], FUS [64], and copper, zinc superoxide dismutase [59].