It is therefore not surprising that Erk1/2 is involved at primary stage in many cellular processes, such as cell growth, cell proliferation and cell differentiation (Lewis T S et al., Adv Cancer Res. 1998, 74: 49-139; Chang F et al., Leukemia 2003, 17 (3): 590-603; Chang F et al., Leukemia 2003, 17 (7): 1263-1293).