PIN1 and leukemia: Inhibition of PIN1 induces the degradation of the fusion oncogene promyelocytic leukemia (PML)–retinoic acid receptor-α (PML–RARα) that drives leukemia stem cells (LSCs), and thereby, treats APL without inducing myeloid differentiation (Ito et al., 2008; de Thé and Chen, 2010).