MAFB and COVID-19: Given that MAFB serves as a negative regulator of GM-CSF signaling (Koshida et al., 2015), downregulation of MAFB expression through modulation of GSK3 activity emerges as a rationale strategy to re-direct pathogenic monocyte-derived macrophages toward the acquisition of a lung-resident alveolar macrophage-like profile during severe COVID-19.