Association of OPRM1 with addiction: a review on drug, alcohol and smoking addiction in worldwide population oleh Vanlal Hriatpuii, Hoikhe Priscilla Sema, Chenkual Vankhuma, Mahalaxmi Iyer, Mohana Devi Subramaniam, Krothapalli R. S. Sambasiva Rao, Balachandar Vellingiri, Nachimuthu Senthil Kumar