IFNA1 and COVID-19: In the meantime, COVID-19 also leads to low expression of maturation markers in DCs, high expression of programmed cell death ligand 1, inability to upregulate DC80 and CD86 in response to ssRNA and other stimuli, decreased secretion of IFN-α and IFN-β, and impaired ability to stimulate T cell proliferation 111, 112.