MAP2K7 and melanoma: MEK inhibitors have been tested extensively in many solid tumors, both as monotherapies and in combination with cytotoxic drug regimens.52 Yet despite the wealth of pre-clinical data posing MAPK as a critical oncogenic pathway, clinical activity has been minimal outside of melanoma.53 In addition to the well-established robustness of the MAPK network due to feedback circuits and pathway cross-talk,54 our results provide two critical explanations for this.