GFAP and infection: Strikingly, we observed abundant infection in astrocytes, as indicated by the presence of viral N protein, S RNA, and dsRNA, with 90% of infected cells expressing glial fibrillary acidic protein (GFAP) or Aquaporin 4 (AQP4) throughout the outer subventricular zone (SVZ) of primary cortical tissue (Fig. 1B).