DPP4 and infection: In SARS-CoV-2 infected astrocytes (Figure 3H), pre-transduction with shDPP4 lentivirus significantly reduced virion production (34 PFU/mL) vs. shScr lentivirus (231 PFU/mL) vs. naïve astrocytes (348 PFU/mL), demonstrating a pronounced effect of DPP4 in permitting a productive infection from SARS-CoV-2.