Idarubicin or 4-demethoxydaunorubicin is an anthracycline antileukemic drug. It inserts itself into DNA and prevents DNA unwinding by interfering with the enzyme topoisomerase II. It is an analog of daunorubicin, but the absence of a methoxy group increases its fat solubility and cellular uptake. Similar to other anthracyclines, it also induces histone eviction from chromatin.