MAP2K7 and neoplasm: Targeted therapy utilizing selective MEK inhibition appears promising for uveal melanoma based on preliminary results of a phase II clinical trial; however, a subset of patients with GNAQ/11 mutation are resistant to this therapy.12,24 It has been suggested that the resistance is due to existence of a unique subset of “MEK-resistant genes” in a subset of GNAQ mutant tumors.12 Our findings provide another possible explanation and suggest that tumor heterogeneity and variability of MAPK activation could be an important cause for therapy resistance.