Adoptive immune cell therapy (ACT) utilizes a patient’s own immune cells to target and eliminate cancer cells. This article explores the application of various cell types in ACT, including T cells, NK cells, macrophages, and dendritic cells. Each cell type offers unique advantages in combating cancer. The article highlights the importance of metabolic regulation in optimizing the anti-tumor function of immune cells. It then explores the immunosuppressive nature of the tumor microenvironment and the role of immune checkpoint molecules in this process. The article concludes by discussing the potential of gene editing tools to improve the efficacy and safety of ACT, while acknowledging the challenges associated with current ACT therapies and outlining future research directions. This approach of harnessing a patient’s own immune system holds promise for a more personalized and effective approach to cancer treatment.