This HTRF kit enables the cell-based quantitative detection of PLK1 phosphorylation at Thr210, activated during cell cycle progression. This HTRF cell-based assay enables the rapid, quantitative detection of PLK1 phosphorylated at Threonine 210. Polo-like kinase 1 (PLK1) is the principle member of the well conserved serine/threonine kinase family and is essential for cell division (mitosis). As such, it is a key regulator of the G2/M checkpoint of the cell cycle PLK1 activation for cell cycle regulation: PLK1 is activated by phosphorylation on Thr210 by AurA kinase. Activated PLK1 phosphorylates CDC25. PLK1 is a critical protein responsible for mitosis and cell cycle progression/cell proliferation. This makes it an attractive cancer treatment target.