The mTOR signalling pathway and the role of mTOR inhibitors in endometriosis. PTEN, phosphatase and tensin homologue; mTOR, mammalian target of rapamycin; PI3K, phosphatidylinositol 3-kinase; Akt, protein kinase B; mTORC1, mammalian target of rapamycin Complex 1; 4EBP1, eukaryotic translation initiation factor 4E-binding protein 1; P70S6K, 70-kDa ribosomal protein S6 kinase.