We have now examined PD-L1 expression and its regulation in NSCLC positive for the EML4-ALK fusion gene.    ///    We have now examined PD-L1 expression and its regulation in NSCLC positive for the EML4-ALK fusion gene.     ///    The PD-L1 expression level was higher in NSCLC cell lines positive for EML4-ALK than in those negative for the fusion gene.     ///    "Finally, the expression level of PD-L1 was positively associated with the presence of EML4-ALK in NSCLC specimens."    ///    "Finally, the expression level of PD-L1 was positively associated with the presence of EML4-ALK in NSCLC specimens. "    ///    "Furthermore, expression of PD-L1 was downregulated by inhibitors of the MEK-ERK and PI3K-AKT signaling pathways in NSCLC cells positive for either EML4-ALK or activating mutations of the EGFR. "    ///    Our findings that both EML4-ALK and mutant EGFR upregulate PD-L1 by activating PI3K-AKT and MEK-ERK signaling pathways in NSCLC reveal a direct link between oncogenic drivers and PD-L1 expression..     ///    Induction of PD-L1 Expression by the EML4-ALK Oncoprotein and Downstream Signaling Pathways in Non-Small Cell Lung Cancer.. 