CXCL8 and endometriosis: The progesterone level in endometriosis patients is lower than the low progesterone level in the follicular phase [3], and progesterone inhibits the occurrence of inflammatory responses by reducing the release of IL-8, inhibiting the NF-κB signaling pathway, as well as COX and prostaglandin synthesis, suggesting that low progesterone levels in endometriosis patients are related to the occurrence of chronic inflammation [28,35].