Recently, Fan et al. evaluated seven cytokines including IL-10, IL-6, IL-4 and IL-2 in serum and peritoneal fluid from endometriosis patients and control patients and found significantly higher levels of IL-10 and lower levels of IL-2 in serum, but significantly higher levels of IL-2 in peritoneal fluid39. The gene discussed is IL10; the disease is endometriosis.