However, we have shown that MEKC121S signaling can be blocked by a moderate increase in the dose of trametinib, a dose that remains significantly lower than that of selumetinib or E6201.40 MEK mutations may be less common than BRAFV600E mutations in primary melanomas, because in our cellular assay, their relative ability to stimulate the MAPK pathway was less than a quarter of the ERK activating activity of BRAFV600E. Here, MAP2K7 is linked to melanoma.