miR-4521 overexpression led to 40.2% and 50.9% decreases of MDM2 and Bcl2, and 60.6% and 39.5% increases of p53 and Bax, respectively, in 786-O (Fig. 7b), which resulted in an MDM2/P53 imbalance and a Bax/Bcl2 increase for decreased proliferation and enhanced apoptosis of renal cancer cells. The gene discussed is TP53; the disease is renal carcinoma.