<p>Adoptive cell transfer (ACT), a fast and promising new advance in immunotherapy for cancer treatment is the chimeric antigen receptor T-cell therapy with the purpose of programming the immune system to attack tumors. Engineered CAR receptors have developed over time depending on the composition of the four generations in the chimeric antigen receptors. Sufficient interleukin-2 (IL-2) is not generated by CAR-T cells in the first generation to exterminate the cancer cells. The next generation adds a secondary single domain such as CD28 and the rapid multiplication of T cells, secretion of cytokine, and immunity to apoptosis. The production of cytokine and killing capability was enhanced by CD3ζ-CD28-41BB or CD3ζ-CD28-OX40 in the third generation, and finally in the fourth generation, the chimeric antigen receptors are known to be T cells that direct for common cytokine-mediated killing that is caused by the addition of interleukin-2 to eradicate cancer cells. Onsets of resistant activation, such as cytokine release syndrome, neurological toxicity, and on-target/off-target recognition, are the difficulties in CAR T cells. The Food and Drug Administration (FDA) approved the successes of this chimeric antigen receptor T cell treatment for hematologic tumors. Moreover, the United States and China are the pioneers in the growth of CAR-T cell therapy. Remarkable results by combination therapies have been created by the clinical trials. To improve T cell efficiency, there is the need to adopt new strategies for various solid tumors to aim at tumor profiles and to minimize toxicity of CAR-T cells.</p>