Moreover, a meta-analysis including 538 OCD cases and 439 healthy controls showed that patients with OCD do not exhibit increased peripheral inflammation during the course of the disease, as no consistent differences in representative biomarkers such as TNF-α, IL-6, IL-1β, IL-4, IL-10 and interferon-γ were found between the two groups [49]. This evidence concerns the gene IL6 and Compulsive behaviors.