IL4 and oral lichen planus: It is well established that OLP was featured by imbalanced Th1/Th2 immune response and Th1/Th2 cytokine profile, with increased T-bet/GATA3 and IFN-γ/IL-4 ratios, which indicated the Th1 inclination for OLP dysimmunity (Lu et al., 2011; Zhou et al., 2012; Hu et al., 2013).