IL-27 favors development of Th1 responses during T cell priming but also exerts potent effects on activated T cells including promoting production of IL-1029,30 and inducing expression of multiple co-inhibitory receptors.31 While none of the nine NSCLC derived CAF lines tested produced IL-27 spontaneously we were surprised to discover that activated T cells (which produced around 4322 pg/ml IFN-γ and 75 pg/ml TNF-α) induce production of IL-27 by fibroblasts (Figure 4d). Here, TNF is linked to non-small cell lung carcinoma.