IL4 and endometriosis: Clinical studies have confirmed close relationship between cytokines and endometriosis, suggesting that cytokines could be used as predictors of this disease.[21] For example, Drosdzol-Cop et al found adolescent patients with endometriosis displayed significantly higher serum IL-4,[15] Othman Eel et al[23] observed serum interleukin-6 measurements discriminate between women with endometriosis and without endometriosis.