This study, Natural Killer Cells: A Guide for Families and Loved Ones of Stage 4 Cancer Patients — Implications for Expanding Cancer Education, highlights the urgent need to integrate education as a core intervention in cancer care. While nearly ten million lives are lost annually to cancer worldwide, much focus remains on chemotherapy and radiation, leaving gaps in understanding the body’s own immune defenses. Natural Killer (NK) cells—described here as the body’s “watchmen”—play a vital role in eliminating abnormal cells before they develop into cancer, yet public awareness is minimal. By translating complex immunology into accessible language and metaphors, this guide empowers families and caregivers with clarity, confidence, and discernment. It stresses the moral and scholarly necessity of education to counter misinformation, reduce vulnerability to predatory practices, and restore agency to families. Combining academic rigor with humanitarian outreach, the study models how cancer education can reshape care and save lives.