A link between neurodegeneration, protein misfolding, and prolyl isomerase activity is further supported by knock-out studies in mice22: when the gene of the prolyl isomerase PPIA is deleted, mice develop a neurodegenerative disease that recapitulates features of FTD, including the aggregation of TDP-43 into cytoplasmic deposits22. This evidence concerns the gene TARDBP and frontotemporal dementia.