(R)-9-(4-(1-(dimethylamino)propan-2-yl)phenyl)-8-hydroxythieno[2,3-c]quinolin-4(5H)-one

OTS964{(R)-9-(4-(1-(dimethylamino)propan-2-yl)phenyl)-8-hydroxy-6-methylthieno[2,3-c] quinolin-4(5H)-one} is a potent TOPK inhibitor with an IC50 value of 28 nM. It is a dimethylated derivative of OTS514. OTS964 can inhibit TOPK kinase activity with high affinity and selectivity. TOPK (T-lymphokine-activated killer cell-originated protein kinase) is a protein that is found in a wide range of human cancers and is believed to work as an oncogene, promoting tumor growth.