High BDNF levels were found to be associated with a good treatment response to lithium.9, 10 Other interesting candidates include oxidative stress markers such as lipid peroxidation, DNA/RNA damage and nitric oxide, neuronal markers such as S100B and Neuron Specific Enolase (NSE), and metabolic markers such as GLP‐1, ghrelin, adiponectin, and GIP.11 No specific genetic maker for BD has been identified, although BD has high heritability.12, 13 The current consensus implicates a role of multiple genetic variants that are dependent on environmental interactions and epigenetic mechanisms. The gene discussed is GIP; the disease is Behcet disease.