GRN and inflammatory bowel disease: As mentioned above, PGRN is involved in regulating the occurrence and development of diseases, including neurodegenerative diseases such as Parkinson’s disease, Creutzfeldt-Jakob disease, motor neuron disease, and Alzheimer’s disease (55–58), and immune-inflammatory diseases such as RA, inflammatory bowel disease, psoriasis, and SLE (60, 65–68).