imaging of conditional gene silencing in vivo using a bioluminescencebased method with thermoinducible micrornas rna interference rnaibased gene therapy has great potential in cancer and infectious disease treatment to correct abnormal upregulation of gene expression we show a new original method uses synthetic micrornas combined with a thermoinducible promoter to reduce specific gene expression the targeted gene is the luciferase firefly reporter gene overexpressed in a subcutaneous tumor which allows the rnai monitoring by bioluminescence imaging bli the inducible inhibition was first demonstrated in vitro using genetically modified cells lines and then in vivo using the corresponding xenograft model in mice achieving spatiotemporal control we demonstrate the feasibility to induce in vivo a specific gene inhibition on demand future applications of this rnaibased gene therapy which can be restricted to pathological tissue would offer wideranging potential for disease treatment