The p28 subunit of IL-27 (IL-27/p28), also known as Interleukin-30 (IL-30), is a member of the IL-12 family of cytokines. When combined with EBI3 (Epstein-Barr virus induced gene 3), p28 forms a heterodimer known as IL-27. p28 is thought to be a proinflammatory cytokine inducing immuno-modulatory effects, but the details of these effects are currently unclear and research is focused on delineating its specific biological functions