IFIT3 and COVID-19: Interestingly, low-density neutrophils - a specific population of neutrophils - are also found in PBMC in addition to monocytes, and low density neutrophil-associated proteins were found to be increased in proteomic profiling of PBMC from COVID-19 patients (Leite et al., 2023) suggesting this cell population might be the source of IFIT3 expression in PBMC.