OAS1 and COVID-19: The causal variant underlying the association of the OAS1/2/3 locus with the susceptibility to severe COVID-19 is likely represented by rs10774671, encoding for a splice-acceptor variant of OAS1, where the protective allele determines the synthesis of a more active prenylated form of OAS1, involved in the intracellular innate immune responses against RNA-viruses, with a capacity for membrane localization (19).