Clinical Precision Medicine: A Primer offers clinicians, researchers and students a practical, up-to-date resource on precision medicine, its evolving technologies, and pathways towards clinical implementation. Early chapters address the fundamentals of molecular biology and gene regulation as they relate to precision medicine, as well as the foundations of heredity and epigenetics. Oncology, an early adopter of precision approaches, is considered with its relationship to genetic variation in drug metabolism, along with tumor immunology and the impact of DNA variation in clinical care. Contributions by Stephanie Kramer, a Clinical Genetic Counselor, also provide current information on prenatal diagnostics and adult genetics that highlight the critical role of genetic counselors in the era of precision medicine.