PLK1 and osteosarcoma: Furthermore, PLK1 has been shown to be involved in cell death processes for many other different types of cancers, including rhabdomyosarcomas, osteosarcomas, hepatocellular carcinomas, esophageal carcinomas as well as hematological malignancies and in this study we intended to focus on novel targets for Ewing's sarcoma [19,37-43].