As a heterodimeric cytokine, interleukin-12 (IL-12) is an initial factor in cellular immune response. IL-12 can activate T lymphocytes and natural killer cells, and stimulate their proliferation and differentiation. IL-12 can also regulate cellular immunity and induce T lymphocytes or NK cell to secrete interferon (IFN)γ This paper reviews the role of IL-12 in a...