– JIB-04 Z-isomer, also known as NSC 693627, is an isomer of JIB-04. JIB-04 is a Jumonji histone demethylase inhibitor. JIB-04 selectively blocks cancer cell growth in vitro and diminishes tumor growth in H358 and A549 mouse xenograft models in vivo. JIB-04 can prolong survival in a mouse model of breast cancer.