Results of the present study are similar to the findings of some earlier studies (37) that demonstrated a significant decrease in IL-4 levels three years after SLIT. Wei et al. (12) also addressed a decline in IL-4 production by TH2 cells after SIT in children with allergic asthma who underwent immunotherapy for 1.5–2 year periods. The gene discussed is IL4; the disease is allergic asthma.