ACE2 and COVID-19: Results indicate certain sites (medulla oblongata, hypothalamus, choroid plexus, and retrograde olfactory route) and cell types (astrocyte, pericyte, radial glial cell, tanycyte, and choroid plexus epithelial cell) are more vulnerable to SARS-CoV-2 infection, highlighting a potential role of astrocyte ACE2 in the neural transmission and pathogenesis of COVID-19.