Mylotarg® (gemtuzumab ozogamicin) was the first ADC to be approved in 2000 for the treatment of acute myeloid leukemia (AML) and was composed of a CD33-targeted antibody linked to the cytotoxic drug calicheamicin via an acid-labile hydrazone linker. This evidence concerns the gene CD33 and acute myeloid leukemia.