Despite its abundance in the central nervous system, the primary function of PPIA remains largely undefined, although it is known to act as a molecular chaperone and interacts with TDP-43 and other heterogenous nuclear ribonucleoproteins, with PPIA levels being reduced in peripheral blood from ALS patients (Luotti et al. 2020). Here, TARDBP is linked to amyotrophic lateral sclerosis.