Interleukin 27 (IL-27) is a heterodimeric protein consisting of EBI-3 (IL-27B) and IL-27p28 (IL-27A). IL-27 forms together with IL-12, IL-23, and IL-35 a family of heterodimeric proteins. Produced as an early product of antigen-presenting cells (APC), IL-27 plays a role in the adaptive immune response by promoting the clonal expansion of naive CD4
+ T-cells. It has also been shown that IL-27 has the ability to induce CD8
+ mediated tumor-specific protective immunity.