Figure 9 compares the nuclear HiF-1α accumulation without therapy and with siRNA therapy. We note that a 5-fold decrease of HiF-1α expression is efficient to decrease the HiF-1α level. For instance, the RCC cells localized in the diagram, presenting a 6-7-fold increase of nuclear HiF-1α level without treatment, and a 2-fold increase after treatment. We then test if the siRNA therapy is able to attenuate the instabilities generated by reoxygenation. Figure 10 shows that a decrease of  attenuates the oscillations. HiF-1α does not exceed any more the normoxic value for a normal cell. This evidence concerns the gene HIF1A and renal cell carcinoma.