RESUMEN
<p><b>OBJECTIVE</b>To review the central role of leukemia stem cells (LSCs) in drug resistance and metastasis, aiming to provide key insights into leukemogenic pathology and developing novel therapeutic strategies against the relapse of leukemia.</p><p><b>DATA SOURCES</b>The data used in this review were obtained mainly from the studies reported in PubMed using the key terms "tumor-initiating cells", "leukemia stem cells", "drug resistance" and "metastasis".</p><p><b>STUDY SELECTION</b>Relevant articles on studies of leukemia stem cells were selected.</p><p><b>RESULTS</b>Increasing numbers of studies have suggested the importance of cancer stem cells (CSCs) in the initiation and maintenance of cancer, especially in leukemia. This review has summarized the origin, characteristics, isolation and identification of LSCs. It highlights the crucial role of LSCs in drug resistance and metastasis of leukemia by illustrating possible mechanisms and aims to provide novel therapeutic strategies for LSCs-targeted treatment.</p><p><b>CONCLUSION</b>LSCs play a crucial role in drug resistance and metastasis of leukemia and new promising LSCs-targeted therapies warrant investigation in both experimental models and clinical practice.</p>