In addition to serum CA125, other potentially useful biomarkers, including peritoneal irrigation, have been mentioned in the literature [18], and several protein isoforms, such as haptoglobin, alpha-1 antitrypsin, S100-A8, and serotransferrin, have been found with higher expression in the peritoneal lavage fluid of patients with endometriosis. This evidence concerns the gene SERPINA1 and endometriosis.