TMPRSS2 and osteosarcoma: We compared these results to those obtained from the analysis of five Non-EwS cell lines, PC-3 (prostate cancer, TMPRSS2-ERG fusion), HEK293 (embryonic kidney), HeLa (cervical cancer), CLB-MA (neuroblastoma), and U2OS (osteosarcoma), and to the putative progenitor cell type of EwS, mesenchymal stem cells (MSCs) (Figure 5B).