QC6352 is an orally active KDM4 inhibitor with anti-tumor and anti-proliferative activity. QC6352 has in vivo inhibitory effects on PDX models of breast and colon cancer and reduces the number of chemoresistant cell populations. QC6352 inhibits KDM4 different isoforms with IC50s of 104 nM (KDM4A), 56 nM (KDM4B), 35 nM (KDM4C), and 104 nM (KDM4D), respectively. QC6352 has moderate inhibitory activity against KDM5 with an IC50 of 750 nM (KDM5B)[1][2].