PD0325901 is a small molecule inhibitor of the mitogen-activated protein kinase kinase (MAPK/ERK kinase or MEK) with potential antineoplastic activity. PD0325901, a derivative of MEK inhibitor CI-1040, selectively binds to and inhibits MEK, which may result in the inhibition of the phosphorylation and activation of MAPK/ERK and the inhibition of tumor cell proliferation It has been shown to improve the reprogramming efficiency of iPSC.