PIAS1 and neoplasm: Strikingly, PIAS1 knockdown for 6 days using the shPIAS1-3 sequence and 1 μg/ml doxycycline resulted in a significant reduction in cell proliferation and tumor volume of PC3 (Fig. 5A, C) and PC3-DR (Fig. 5B, D) onplants in the CAM experiment.