EBI3 and neoplasm: Interleukin (IL)-35 is an immunosuppressive cytokine involved in tumour immune escape because it induces Treg cells.8–10 IL-35 is a heterodimer of the IL-12 family of cytokine composed by IL-12p35 subunit and IL-27β subunit Epstein–Barr virus induced 3 (EBI3).11 IL-35 has been shown to exhibit immunosuppressive activities that are not present in the other members of IL-12 family.12,13 It is expressed primarily by antigen-presenting cells like tolerogenic dendritic cells.14 IL-35 can directly suppress effector T cell proliferation and function.