MAPK14 and neoplasm: Subsequently, using Δex8 mice in the two-step DMBA skin carcinogenesis model it was then proved that in addition to the early tumor-suppressing function of MK5/PRAK a late tumor-promoting function of the p38-MK5/PRAK pathway exists, where MK5/PRAK acts as an angiogenic and cell migration stimulating host factor [11].