FAS and COVID-19: In this study, polymorphisms in the FAS and FASL genes were not directly associated with the severity of COVID-19, but it was possible to identify that the FAS rs1800682 (A/G) and FASL rs763110 (C/T) variations can influence the expression levels of FAS and FASL and contribute to the number of COVID-19 symptoms, showing that these polymorphisms can be considered one of the factors that influence, in part, the pathogenesis of SARS-CoV-2 infection, although it is not a determinant of the severity of the disease.