IL4 and asthma: The current study aimed at determining the key parameters of Th2 (IL-4 and GATA3) and Treg (TGF-β and FOXP3) cells in the peripheral blood of patients with asthma and evaluating the production of Th2- and Treg-type cytokines (IL-4 and TGF-β) by unstimulated and stimulated peripheral blood mononuclear cells (PBMCs) isolated from patients after in vitro culturing.