GRPR and ovarian cancer: Several receptors have been found to be upregulated in ovarian cancer tissues, including growth hormone releasing hormone receptor (GHRHR) [283], GRPR [284], leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) [269,270], oxytocin receptor (OXTR) and parathyroid hormone 2 receptor (PTH2R) [210].