After correcting for multiple comparisons and using the model corrected with the additional sample handling markers, we found that pre-treatment levels of IL8 in CSF, but not plasma, in both Multiplex cohorts were upregulated in patients with GBS compared to all other groups, i.e., HC, CIDP, NIP and ALS (pFDR < 0.05) (Figures 1A–C; Table 3). Here, CXCL8 is linked to Guillain-Barre syndrome.