CX3CR1 and lung cancer: Given that fully-differentiated Teff (and a subset of CX3CR1+Tems) express IFN-γ and exert cytotoxic activity in patients with lung cancer [8, 12, 13], we sought to identify master regulon(s) that may contribute to CD8+ differentiation along the cytotoxic effector trajectory in NSCLC tumors.