Abstract: @@ Polo-like kinase 1(PLK1) plays an important role in many cell-cycle-related events.1 At G2/M transition, PLK1 contributes to the activation of cyclinB/Cdc by phosphorylation of Cdc25C, centrosome functional maturation, bipolar spindle formation. In later stage of mitosis, PLK1 is involved in regulating components of the anaphase-promoting complex (APC) for mitotic exit and in the execution of cytokinesis.