IL4 and contact dermatitis: To understand the preventive mechanism against the contact dermatitis model observed with administration of the IJH-SONE68-derived EPSs, the mRNA expression levels of T helper (Th) 1-type (interferon (IFN)-γ) and Th2-type (interleukin (IL)-4, 5, and 13) inflammatory cytokines in ear tissue were measured using quantitative reverse transcriptional (qRT)-PCR analysis.