This case study follows the diagnosis and treatment of “Steven,” a patient detected with hepatocellular carcinoma (HCC) due to cirrhosis. In this story, Steven’s oncologist uses immunotherapy to treat Steven, giving students an opportunity to examine why immunotherapy may be more beneficial than chemotherapy or radiation therapy in certain situations. This case study is designed to aid students in integrating the concepts of molecular biology, immunology, and cancer stem cell (CSC) theory to allow the application of their knowledge in a specific setting. They learn about HCC as a disease, the cell-surface antigen CD 133 and its role as a CSC biomarker, CAR T-cell therapy, and the engineering of CAR T-cells to target CD 133 as a potential immunotherapeutic strategy. This case study is best suited for an undergraduate molecular biology course or similar courses in which the concepts of genetics, protein-protein interactions, cancer, and basic immunology are covered.