The human IL-12 R subunit is a member of the cytokine receptor superfamily and the functional high-affinity IL-12R is composed of at least two beta-type cytokine receptor subunits, each independently exhibiting a low affinity for IL-12. IL-12RB2 is the signaling component coupling to the JAK2/STAT4 pathway. Promotes the proliferation of T-cells as well as NK cells. Induces the promotion of T-cells towards the Th1 phenotype by strongly enhancing IFN-gamma production. IL-12B2 gene acts as tumor suppressor in human acute and chronic B-cell leukemias/lymphomas? IL-12R beta 2 directly restrains multiple myeloma cell growth, and targeting of IL-12 to tumor cells holds promise as new therapeutic strategy.