The combined administration of ATO + ATRA shows synergistic effects by dual-targeting of promyelocytic leukaemia protein (PML)–retinoic acid receptor alpha (RARα), the expression product of the characteristic t(15,17) translocation, which is responsible for the differentiation blockade in APL (Testa and Lo-Coco, 2015; de Thé, 2018). Here, PML is linked to acute promyelocytic leukemia.