LEP and glioblastoma: Antagonism of ObR in glioblastoma cell lines peptide inhibits proliferation and invasiveness, and is associated with downregulation of leptin-responsive genes such as cyclin D1 (CCDN1), survivin (BIRC5), heat shock protein (HSP90A), hypoxia inducible factor (HIF1A) and vascular endothelial growth factor (VEGF) [19].