Researchers at the Pennsylvania State University College of Medicine, have discovered the mechanism by which a low dose of the opioid antagonist naltrexone (LDN) can suppress cell proliferative-related disorders such as cancer and autoimmune diseases. LDN causes a compensatory increase in an endogenous opioid, the opioid growth factor (OGF, [Met5]-enkephalin), and the OGF receptor (OGFr).

Source: Low-dose naltrexone (LDN): Tricking the body to heal itself | EurekAlert! Science News