PTC-209 HBr is the hydrobromide salt of PTC-209. PTC-209 is a potent and selective BMI-1 inhibitor with IC50 of 0.5 μM in HEK293T cell line, and results in irreversible reduction of cancer-initiating cells (CICs).
PRT 4165 is an inhibitor of Bmi1/Ring1A, subunits of the polycomb repressive complex 1 (PRC1). It prevents Bmi1/Ring1A-mediated ubiquitination and drug-induced degradation of topoisomerase 2alpha.