CTSL and COVID-19: Using CTSL as a marker for viral entry gene expression, it was compared to the expression of type I IFN antiviral response genes (IFITM3, MX1, SAMHD1, and TRIM25) in GSE157103, which includes a large transcriptomic dataset from hospitalized COVID-19 patients requiring non-ICU care (50), ICU-level care (50), as well as 26 control patients without COVID-19.