To test the acute role of Pax3:Foxo1a in tolerization to treatment-related DNA damage in vivo, we used eYFP siRNA to transiently knock down Pax3:Foxo1a in aRMS tumor cells treated with radiation versus non-irradiated controls that were then orthotopically injected into unirradiated host mice. Here, PAX3 is linked to neoplasm.