MAPK1 and non-small cell lung carcinoma: To investigate whether inhibiting MEK, an upstream regulator of ERK signaling, affects Hippo pathway activity, we analyzed YAP expression in NSCLC A549 cells treated with the MEK1/2 inhibitor Trametinib (N-(3-(3-cyclopropyl-5-(2-fluoro-4-iodophenylamino)-6, 8-dimethyl-2, 4, 7-trioxo-3, 4, 6, 7-tetrahydropyrido [4,3-d] pyrimidin-1(2H)-yl) phenyl) acetamide, GSK1120212 [29] or the ERK inhibitor FR180204.