MAPK8 and neoplasm: When we evaluated JIMT-1 derived xenograft tumor growth in mice treated with either placebo, the vehicle in which the inhibitor was mixed (see Methods section), or the JNK inhibitor, SP600125 (30 mg/kg), we found a significant delay (6.9 days) in the median time for the tumors of SP600125 treated animals to reach a volume of ~600 mm3 (Fig 2B).