GFAP and Creutzfeldt Jacob disease: Glial fibrillary acidic protein (GFAP), indicative of astrocytes, and superoxide dismutase 1 (SOD1), indicative of oxidative stress, showed a small decrease by western blot in the NPC-seeded CJD-infected organoids compared with the unseeded CJD-infected COs (Additional file 1: Fig. S7A & B).