Ten studies investigated the role of fifty-one polymorphisms of seventeen other genes in BD comorbid to SUD: PON1, ALDH2, ADH1B, NGFB, GHRH, PREB, GROK5, BDKRB2, CHRNB3, CHRNA5, CHRNA3, IL1b, NOS1AP, TRPM2, NR4A1, NR4A2, NR4A3, TSPO, and TRACR1. The gene discussed is NR4A2; the disease is Behcet disease.