To decipher the mechanism of action of SkE, we used both melanoma and CML cell lines and primary cells from patients diagnosed with melanoma and HCL and demonstrated that low concentrations of SkE interfere with the activation of ERK, as shown by the clear inhibition of ERK1/2 phosphorylation. This evidence concerns the gene MAPK3 and chronic myelogenous leukemia, BCR-ABL1 positive.