TTR and Alzheimer disease: Interestingly, our study also proved that only in the ATTR‐PN group was the MFD negatively correlated with the course of disease, indicating ATTR‐PN was a relatively severe chronic progressive disease that was similar to neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and Amyotrophic lateral sclerosis, with abnormal protein aggregation and no relapse or remission in the course of disease.31