CXCL10 and influenza: Comparison of cytokine expression profiles between critically ill, severe, and moderate COVID-19 cases revealed a significant association of IP-10 with disease severity.43 Previous studies demonstrated that IP-10 is one of the most abundant and the earliest chemokines associated with BBB damage in various viral infections.44 Besides COVID-19, IP-10 was also associated with the severity of diseases caused by other viruses such as MERS-CoV and influenza.45,46 Inducible protein 10 is considered as a biomarker of multiple CNS diseases and closely correlates with BBB pathological changes.47–49