The study by Zakharyan et al. demonstrated that the IL-6 −174G/C polymorphism is associated with increased plasma IL-6 in schizophrenia patients and constitutes a risk factor for the disorder (118), and a study by Frydecka et al. indicated that elevated IL-6 in schizophrenia patients is not due to genetic variation (123). Here, IL6 is linked to schizophrenia.