FCN1 and COVID-19: In addition, MAFB silencing also impaired the acquisition of the genes that define the proinflammatory macrophage subsets in COVID-19 (MoAM1, MoAM2, FCN1+) (Figure 5E), indicating that MAFB also influences the transcriptome of the macrophage subsets that are responsible for the production of proinflammatory factors in severe COVID-19.