Both curcumin and the potent RL197 analog induced ROS (Figure5A) and decreased expression of Sp1, Sp3, Sp4 and Sp-regulated proteins (Figures2 and3) in colon cancer cells, and cotreatment with GSH inhibited these responses and also partially reversed the growth inhibitory effects of these compounds (Figure5D). Here, SP3 is linked to malignant colon neoplasm.