**3.6 IL-28 and IL-29**

IL-29, IL-28A and IL-28B are subgroups of Type III IFNs known as IFN-λs that induce activation of the Jak/STAT signaling pathway and modulating the Th1/Th2 response [66, 67]. The first relationship between IL-28 and IL-29 and BD was investigated in a study from Turkey. Genc et al. showed that the GG genotype of rs8099917 (IL28 G/T) might be a protective factor against BD. They also found a significant difference between patients with and without central nervous system (CNS) involvement in rs12979860 (IL28 C/T) polymorphism [68].
