Full name: Interleukin-12

Aliases:1,2 IL-12A, IL-12B, CLMF, NFSK, and NKSF

Size:3 75 kDa

Family:3,4 IL-12 family (IL-12, IL-23, IL-27, and IL-35)

Receptors:3 IL-12Rβ1 and IL-12Rβ2

Major cellular sources:3,4 DCs, macrophages, activated monocytes, neutrophils, microglia, and B cells

Major cellular targets:3 T cells Th1 cells, NK cells, and DCs

Disease states associated with:3,4 Bacterial infections, inflammatory bowel disease, psoriasis, chronic inflammatory diseases, and autoimmune diseases

Major physiologic functions:

  • Members of the IL-12 cytokine family are important regulators of host immunity.4

  • IL-12 is a pro-inflammatory cytokine that mediates the development and maintenance of Th1 cells by inducing IFN-γ production by Th1 and NK cells.3

  • IL-12 plays an important role in the induction of ILC1s.3

  • IL-12 indirectly activates the antimicrobial, antiparasitic, and antitumor activities of macrophages and promotes the cytolytic activity of NK cells and lymphokine-activated killer cells.3

  • IL-12 has also been associated with autoimmune response and IL-12–induced differentiation of Th1 cells and is speculated to be associated with the development of various organ-specific autoimmune diseases.4

  • An additional function of IL-12 is controlling the homeostasis of Treg cells by eliminating them.3

CLMF: cytotoxic lymphocyte maturation factor; DC: dendritic cell; IFN-γ: interferon-gamma; IL: interleukin; IL-12R: IL-12 receptor; ILC: innate lymphoid cell; NK: natural killer; NFSK: NF cell stimulatory factor; NKSF: natural killer cell stimulatory factor; Th: T helper; Treg: regulatory T.


  • 1.

    NCBI. Gene. IL12A interleukin 12A [Homo sapiens (human)]. Accessed March 11, 2021.

  • 2.

    NCBI. Gene. IL12B interleukin 12B [Homo sapiens (human)]. Accessed March 11, 2021.

  • 3.

    Akdis M, Aab A, Altunbulakli C, et al. J Allergy Clin Immunol. 2016;138:984-1010.

  • 4.

    Sun L, He C, Nair L, et al. Cytokine. 2015;75:249-255.