This book discusses the recent developments in the therapeutic implications of cancer stem cells for the effective diagnosis, prognosis, and treatment of cancer. It summarizes the various stem cells of common cancers including colon, pancreas, lungs, prostate, melanoma, and glioblastoma, and reviews the potential role of cancer stem cells in tissue aggressiveness, examining the functional contribution of cancer stem cells in the establishment and recurrence of cancerous tumors. Further, it explores the potential of cancer stem cells as novel therapeutic targets for the treatment and prevention of tumor progression. The book also discusses the various approaches for detecting, isolating, and characterizing different cancer stem cells and signaling pathways that control their replication, survival, and differentiation. Lastly, it explores the key features and mechanisms of drug resistance, chemo-resistance, and radio-resistance in cancer stem cells to improve therapeutic rationale.