IL4R and COVID-19: As for the inflamed tissue, when analyzing the cells from the BALF of patients with severe COVID-19, upregulation of the genes encoding key factors responsible for the polarization of cells towards Th2 (GATA3, IL4R, and MAF) was found, although the production levels of the main Th2 cytokines did not differ between patients with different severities of COVID-19 [120].