This handbook comprehensively explores various facets of stem cells and their secretome in the field of regenerative medicine, covering topics such as the biology, characteristics, and applications of mesenchymal and non-mesenchymal stem cells in diverse medical contexts. It delves into their potential for treatment of radiation injuries, diabetes, aging-related diseases, osteoarthritis, Alzheimer's disease, and oral surgery. Furthermore, it investigates the potential of neuronal stem cells for neural repair, myoblast implants for Duchenne muscular dystrophy, and immunotherapy using non-genetically modified natural killer cells. The book also uncovers the possibilities of botanical leads for stem cell therapy, explores the role of stem cells in promoting healthy aging, and sheds light on their complex interplay with cancer, particularly in gliomas and gynecologic cancers. Additionally, it reviews the use of stem cell-derived insoluble factors, focusing on extracellular vesicles as therapeutic agents in dentistry, cardiovascular diseases, and neurodegenerative disorders. The chapters discuss the potential of engineering mesenchymal stem cells secretome for bone regeneration and treating intracerebral hemorrhage. Towards the end, the book elucidates cell-free scaffolding for tissue engineering, adult stem cells' disease tropism, and the evolving strategies in regenerative medicine. It is intended for researchers, professionals, and academicians in the fields of regenerative medicine, stem cell biology, and medical biotechnology.