Recently, there has been a breakthrough in immunotherapy. The development of the advanced therapy medicinal product (ATMP) is a striking example of that. Chimeric antigen receptors T cell therapy (CAR-T therapy) is the result of cooperation between biotechnologists, oncologists and immunologists. This article deals with the issues related to the development of CAR-T technology. The basics of CAR-T design and the mechanism of this therapy action are discussed. Its successes were indicated mainly in the treatment of patients with leukemias and lymphomas. EGFRvIII as an exemplary target for the therapy of solid tumors is described. However, it was pointed out what difficulties the therapy against mutated variant of epidermal growth factor receptor EGFRvIII-positive cells encounters. The growing importance of PSMA and GD2 as targets for CAR-T was also pointed out. New trends in this technology, such as the next generations of CAR-T and development of CAR-M, were noticed. Finally, the potential of CAR-T treatment in non-cancerous diseases, such as cardiac diseases, allergies or infectious diseases, including COVID-19, was characterized.