ALK and lung cancer: Decreased expression of the phosphatase DUSP6 leading to rescue of phospho-ERK and reactivation of MAPK signaling was observed in ALK inhibitor-resistant cell lines and patient samples.40 Similarly, downregulation of NF1, leading to reduced levels of the Ras-GTPase activating protein neurofibromin, and thus increased Ras activity, has been identified as a driver of resistance to EGFR inhibition in lung cancer.42