Inspired by a recent study showing that screening the activities of more than 60 kinases in cell lines and in human tumor samples allowed the identification of kinases that are therapeutically relevant in the context of BRAFV600E-driven tumors [62], we used a phosphosite-specific kinase activity array system to assay the activity of tyrosine kinases towards 196 target peptides and of serine/threonine kinases towards 144 target peptides in nine different sets of mouse and human parental, MEKi-, ERKi- or MEKi/ERKi-resistant cells. Here, MARK2 is linked to neoplasm.