Work on non-small cell lung cancer has shown that inhibiting mitogen-activated protein kinase kinases (MEKs) triggers CXCL10 secretion, resulting in recruitment of CD8+ T cells presenting with CXCR3 [Fig. 2(a)]; conversely, activation of components of the hedgehog pathway in tumor cells has been shown to promote TAM M2 polarization, thus downregulating expression of CXCL9 and CXCL10 and limiting CD8+ T cell recruitment.74–77. This evidence concerns the gene CD8A and non-small cell lung carcinoma.