PROS1 and metastatic neoplasm: Comparing the genomic data of three FN-RMS cell lines with our cohort of tumors, we found several candidate genes (Fig 3) in which loss has been associated with tumor progression in other neoplasms.21,22 For instance, loss of PROS1 was found to be associated with metastatic disease in uveal melanoma by broad copy number analysis, together with loss of CCDC50.