MAP2K1 and neoplasm: Furthermore, in a mouse skin carcinogenesis model, 7,12‐dimethylbenz[a]anthracene (DMBA)/12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced tumor formation was profoundly suppressed in MEK1‐deficient mice as compared with wild‐type mice, whereas no obvious inhibitory effect was observed in MEK2‐deficient mice [34].