Indeed, inhibition of RAF-MEK-ERK kinases can result in decrease in tumor cell proliferation and induce apoptosis.5,6 Many pharmaceutical companies have developed MEK kinase inhibitors, but the clinical benefit of these inhibitors has been disappointing to date.7–9 A notable exception is the use of MEK inhibitors in BRAF or NRAS mutant melanomas.10,11 Thus, identifying predictive biomarkers for MEK inhibitor response and potential combination therapies that enhance MEK inhibitor effectiveness is essential for the future clinical use of these drugs. Here, MAP2K7 is linked to melanoma.