This latter CD40-dependent mechanism is likely to be the principal mechanism for the production of IL-12 in cancer.72 IL-12 binds to the IL-12 receptor (IL-12R), expressed as a high-affinity heterodimer of IL-12Rβ1 and IL-12Rβ2 subunits mostly on T cells and NK cells. Here, IL12RB1 is linked to cancer.