PLK1(Polo-like kinase 1), also named as PLK and STPK13, belongs to the protein kinase superfamily, Ser/Thr protein kinase family and CDC5/Polo subfamily. PLK1 is a Serine/threonine-protein kinase that performs several important functions throughout M phase of the cell cycle, including the regulation of centrosome maturation and spindle assembly, the removal of cohesins from chromosome arms, the inactivation of APC/C inhibitors, and the regulation of mitotic exit and cytokinesis.The localization of Polo changes during the cell cycle. In interphase, Polo shows a mostly diffuse cytoplasmic localization. Polo becomes concentrated on centrosomes from early prophase and appears on centromeres or kinetochores from late prophase, before nuclear envelope breakdown (NEB). After anaphase onset, Polo relocalizes to the central spindle and remains enriched at the midbody ring in late stages of cytokinesis (PMID: 29167465).