A classic example is gemtuzumab ozogamicin (GO) [221,222], which consists of calicheamicin linked to an anti-CD33 antibody and has entered multiple phase III clinical trials for adult and pediatric AML patients harboring diverse cytogenetic phenotypes, such as nucleophosmin1 (NPM1)-mutated [223] and lysine methyltransferase 2A (KMT2A)-rearranged AML subtypes [224,225]. Here, CD33 is linked to acute myeloid leukemia.