TNKS1/2-IN-2 (Compound 21) is a potent and selective tankyrases inhibitor. TNKS1/2-IN-2 exhibits IC50 values of 4 nM and 63 nM against TNK1 and TNK2 in the enzymatic assay, respectively. TNKS1/2-IN-2 inhibits proliferation of A549 and H292 cell lines with IC50 values of 39.5 nM and 12.8 nM, respectively. TNKS1/2-IN-2 can be used for the research of cancer[1].