To confirm that downregulation of Noxa by PLX4720 in BRAFV600E melanoma cells is due to inhibition of the MEK/ERK pathway, we treated IgR3 and MM200 (BRAFV600E), and Mel-RM and ME4405 (BRAFWT) cells with the MEK inhibitor U0126. Here, MAPK1 is linked to melanoma.