Both trametinib and selumetinib showed selective potency in NRAS mutant cell lines (IC50 in DFCI168: trametinib 2 nm; selumetinib 50 nm), but not in NRAS WT SCLC cell lines (Fig. 2B), despite ERK phosphorylation being significantly suppressed upon MEK inhibition in both SCLC subtypes (Fig. 2C). Here, MAP2K7 is linked to small cell lung carcinoma.