SSR1 and multiple sclerosis: CNS: central nervous system, fMRI: functional magnetic resonance imaging, MRI: magnetic resonance imaging, MS: multiple sclerosis, PD: Parkinson's disease, PET/MR: positron emission tomography/magnetic resonance, PPI: protein-protein interaction, SSR1: signal sequence receptor subunit 1, WA: whisk assist, WGCNA: weighted gene co-expression network analysis