Ilaprazole (IY-81149) is an orally active proton pump inhibitor. Ilaprazole irreversibly inhibits H+/K+-ATPase in a dose-dependent manner with an IC50 of pump inhibitory activity of 6 μM in rabbit parietal cell preparation. Ilaprazole is used for the research of gastric ulcers. Ilaprazole is also a potent TOPK (T-lymphokine-activated killer cell-originated protein kinase) inhibitor