Polo-like kinase 4 (PLK4), originally identified in Drosophila as a serine/threonine kinase and mapped to chromosome 4 q28 which is a region frequently associated with loss of heterozygosity (LOH) in hepatoma [15], is essential for centriole duplication and cell cycle progression [16], [17]. This evidence concerns the gene PLK4 and hepatocellular carcinoma.