The book entitled "STEM CELLS" provides a comprehensive overview of the field, covering everything from the basic biology of stem cells to their diverse applications in regenerative medicine, disease modeling, transplantation, and cancer research. Each unit and chapter delves into key concepts, methodologies, ethical considerations, and real-world implications, offering a thorough understanding of the multifaceted nature of stem cell science. Throughout the book, readers will gain insights into the historical context and milestones that have shaped stem cell research, as well as the current state of the field and future directions. The ethical, legal, and social implications of stem cell technologies are also examined, highlighting the importance of responsible conduct, regulatory oversight, and equitable access to ensure that the benefits of stem cell therapies are maximized while minimizing potential risks and disparities. Overall, "STEM CELLS" serves as a valuable resource for students, researchers, healthcare professionals, policymakers, and anyone interested in the transformative potential of stem cell science.