Interleukin-12 receptor subunit beta-2 (IL12RB2), also known as IL-12 receptor subunit beta-2, IL-12R subunit beta-2, IL-12R-beta-2, and IL-12RB2, is a type I transmembrane protein identified as a subunit of the interleukin 12 receptor complex. IL12RB2 belongs to the type I cytokine receptor family. The coexpression of IL12RB2 and IL12RB1 proteins was shown to lead to the formation of high-affinity IL12 binding sites and reconstitution of IL12 dependent signaling. The expression of IL12RB2 is up-regulated by IFN gamma in Th1 cells and plays a role in Th1 cell differentiation. The up-regulation of IL12RB2 is found to be associated with some infectious diseases, such as Crohn's disease and leprosy, which is thought to contribute to the inflammatory response and host defense. This subunit is the signaling component coupling to the JAK2/STAT4 pathway. IL12RB2 promotes the proliferation of T-cells as well as NK cells. IL12RB2 induces the promotion of T-cells towards the Th1 phenotype by strongly enhancing IFN-gamma production.