This textbook explores the revolutionary field of gene therapy, examining its potential to treat and cure a wide range of genetic and acquired diseases. It introduces key concepts in cellular and molecular biology relevant to gene therapy, including gene transfer methods, genome editing, and nucleic acid-based vaccines. Special attention is given to the clinical relevance and practical applications of these technologies. The chapters cover topics such as the design and use of viral and non-viral vectors, genome editing tools like CRISPR, transgenic animal models, and therapeutic strategies for hereditary and non-hereditary conditions, including cancer. It provides case studies of groundbreaking therapies that have reached clinical trials and highlights the successes and challenges faced by researchers and healthcare professionals in this rapidly evolving field. Additionally, the book addresses the regulatory landscape and future implications of gene therapy for personalized medicine. This textbook is designed for undergraduate and postgraduate students in biotechnology, molecular biology, and medical sciences, as well as healthcare professionals and researchers working in biomedical fields. It is also valuable for policy advisors and readers interested in understanding the future of precision medicine and therapeutic innovation.