High levels of Endo180 protein have been reported previously in osteosarcomas (17, 19, 21), with Endo180 identified as one of the most upregulated genes in proteomic profiling, transcriptomic analysis, and IHC staining of osteosarcoma patient samples and cell lines, compared with normal tissues and other pediatric cancers (21). This evidence concerns the gene MRC2 and childhood malignant neoplasm.