In contrast, treatment with the MEK inhibitor refametinib resulted in dramatic tumor shrinkage in virtually all animals only 5 to 9 days post treatment onset (>50% reduction in tumor volume in 80% of mice) as calculated from T2w-MRI data (Fig. 1b,c) supporting a suitable model system to study early response monitoring of treatment effects. This evidence concerns the gene MAP2K7 and neoplasm.