The pregnancy hormone Relaxin relieves you of acute and chronic pain (No kidding): Relaxin-based activation of the PD-1 pathway for Pain therapy: Relaxin, a protein hormone that facilitates labor and relaxes the uterine musculature,  increases the expression of PD-L1, attenuates acute and chronic pain, and suppresses mechanical and thermal hypersensitivity and inhibits nociceptive neuron excitability, via up-regulation of its target gene, 24/August/2018, 11.08 pm