OXTR and breast cancer: The level of this receptor was high in MDA-MB-231 cells, and a high expression of oxytocin receptors has been associated with an enhanced metastasis capacity; in fact, metastasized tumors showed a higher expression of oxytocin receptors than the corresponding primary tumors, and a high expression of oxytocin receptors increased tumor cell migration, via the ERK1/2-RSK-rpS6 signaling pathway, and decreased survival in triple-negative BC individuals [139].