In neurodegenerative diseases, progranulin and/or GRNs are detected within amyloid deposits (Gliebus et al., 2009; Gowrishankar et al., 2015; Mendsaikhan et al., 2019b), suggesting that progranulin may have additional extracellular roles in the formation of neurodegeneration-related protein aggregates. Here, GRN is linked to neurodegenerative disease.