The powerful combination of lentivirus transfection and non-invasive apoptosis detection sensor (NIADS) detection has the advantage of being easy to handle and performing the quantitative and kinetic analyses of apoptotic cell death by HDAC or anti-cancer drugs on cells, compared to other apoptosis detection assays such as apoptotic protein activation, flow cytometry and LIVE/DEAD cell assays. This evidence concerns the gene HDAC9 and cancer.