In order to assess the physiological significance of Smurf2-CNKSR2 interaction, we stably knocked down Smurf2 using Smurf2 shRNA in MDA-MB-231 cells, and observed that Smurf2 knockdown induced CNKSR2 degradation (Fig. 11), which leads to reduced pro-proliferative and tumorigenic properties of breast cancer cells. The gene discussed is CNKSR2; the disease is breast cancer.