PGN immunodetection was co-localized with immunoreactivity to the astrocytic protein, glial fibrillary acidic protein (GFAP in both MS and nonMS cases (Fig. 3c1 inset, Fig. 3e1, Supplementary Fig. 3b1,b2) and the microglial protein, Iba-1 (inset Fig. 3c2, Supplementary Fig 3a1,a2, respectively) with approximately 50% of each cell type associated with PGN immunopositive structures (Supplementary Fig. 3c,d). The gene discussed is GFAP; the disease is myeloid sarcoma.