To verify the expression of IL-33 and ST2 (interleukin receptor-like 1), a widely accepted receptor of IL-33, in endometriosis (EMs) patients, we employed immunohistochemistry (IHC) assays on both normal endometrial (EN) and ectopic endometrial tissues (EC) [20]. Here, IL1RL1 is linked to eosinophilia-myalgia syndrome.