TGFB1 and cancer: To analyze a potentially direct impact of IL-27 on fibroblasts, 3T3 murine fibroblasts were stimulated with transforming growth factor β (TGFβ) to induce a cancer-associated fibroblast phenotype (27), with or without the addition of IL-27, and several fibroblast activation and proliferation markers were analyzed (Supplementary Figure 4C).