TGFB1 and endometriosis: They indicate that miR-21 mediates post-transcriptional regulation in peripheral blood mononuclear cells (PBMCs) in women with endometriosis and regulates transcripts in the studied molecular network associated with endometriosis, with the strongest correlation detected between miR-21 and TGF-β1, which confirms that this gene is a direct target for miR-21.