It was previously shown that IFITM3 facilitates replication of the seasonal coronavirus hCoV-OC43 [74], while we and others recently showed that SARS-CoV-1 and SARS-CoV-2 infection is inhibited by ectopic and endogenous IFITM1, IFITM2, and IFITM3 from mice and humans [75–79]. Here, IFITM3 is linked to COVID-19.