P2RX7 and myeloid sarcoma: Interestingly, total P2X7 receptor levels remained high in the brain of EAE rats even 20 days after immunization and it correlates to increased levels of glial fibrillary acidic protein (GAFP), a marker of astrocyte activation, suggesting a role for P2X7 receptor activation in the sustained astrocytosis that is observed in the advanced stages of the disease, in both EAE and MS, despite clinical recovery (Holley et al., 2003; Grygorowicz et al., 2011).