MMP9 and endometriosis: Expression of MMP-9 by EESCs and EuESCs increases in endometriosis in response to inflammatory conditions in the peritoneal cavity, which is higher in ectopic than eutopic lesions and activation of the NF-κB and MAP-kinase signaling and other inflammatory pathways, as well as to increased oxidative stress43,44; This assists the replacement, growth, and invasion of endometriotic implants20,21.