Protein folding is tightly regulated by molecular chaperones and other protein quality control mechanisms such as the ubiquitin proteasome system and autophagy to ensure the integrity of the proteome. However, these systems can fail to prevent protein misfolding, leading to protein aggregation and amyloidosis. They are underlying reasons for many neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease or Huntington’s disease. Interfering with protein quality control systems and modulating posttranslational modifications of proteins can reduce aggregation, ameliorate amyloidosis and can have profound effects on the immune system.