Leptin may also contribute to the migration and invasion abilities of non-cancer cells, for example, endometriotic cells via the up-regulation of MMP-2 through an ObR-dependent JAK2/STAT3 signaling pathway [119] and human trophoblastic cells through MMP-14 overexpression, requiring the crosstalk between neurogenic locus notch homolog protein 1 (Notch1) and PI3K/AKT signaling pathways [120] as well as by regulating the expressions of MMP-9, TIMP1, TIMP2 and E-cadherin [121]. The gene discussed is MMP9; the disease is cancer.