PLK1 also known as PLK is a serine/threonine kinase that is closely related to polo and CDC5, genes that are required for passage through mitosis in Drosophila and Saccharomyces, respectively. PLK1 plays a crucial role in cell cycle regulation, particularly during mitosis. PLK1 is predominantly located in the cytoplasm and accumulates during the S and G2 phases of the cell cycle, with levels peaking at the onset of mitosis before rapidly decreasing post-mitosis. PLK1 regulation is vital, as activity is closely linked to cell proliferation and the maintenance of genomic stability. Elevated expression of Plk has been observed in various tumors, suggesting potential as a biomarker for cancer progression and a target for therapeutic intervention.