OXTR and breast cancer: In fact, oxytocin can inhibit breast cancer cell proliferation through the activation of its receptor (OTR), a member of the G protein-coupled receptor family, triggering an intracellular signaling cascade that can lead to apoptosis, cell cycle arrest, and the suppression of pro-tumor pathways such as PI3K/Akt and ERK [68,69,70,71,72,73].