Cell therapy includes a wide range of cell-based therapies for the treatment of human illnesses, including the use of immune cells, particularly T cells to fight tumors and the regulation of inflammatory immune responses. In this review, we concentrate on cell therapy in the immuno-oncology field, which is largely motivated by clinics’ desires and requests for better treatments to combat a variety of difficult-to-treat cancers. We talk about recent developments in a variety of cell therapies, such as natural killer cells, tumor-infiltrating lymphocytes, chimeric antigen receptor ( CAR ) – T cells. The current review focuses in particular on how to enhance therapeutic responses by enhancing tumor recognition or the ability of immune cells infused within the tumor microenvironment to be resilient. Finally, we talk about the potential of other immune cell types that are currently being investigated as promising CAR-cell alternatives that aim to overcome the drawbacks of traditional adoptive cell therapies.