In accordance to our findings, other studies also demonstrated that SFN potentiated the analgesic effects of specific DOR agonists, such as DPDPE and SNC-80, in animals with diabetic neuropathy (McDonnell et al., 2017a) and improved the local antiallodynic and/or antihyperalgesic effects of MOR agonists, for example morphine, under inflammatory and neuropathic pain conditions (Redondo et al., 2017; Ferreira-Chamorro et al., 2018). The gene discussed is OPRM1; the disease is diabetic neuropathy.