With the aim of improving the treatment result of CAR therapy, intended is to provide an effective means for the cytokine release syndrome, as an alternative to the administration of the anti-IL-6 receptor antibody or the like. Together with the target antigen-specific chimeric antigen receptor gene, a first nucleic acid construct which intracellularly producing an siRNA targeting interleukin-6 gene and/or a second nucleic acid construct which intracellularly producing an siRNA targeting tumor necrosis factor α gene are introduced into the target cell, thus preparing the gene-modified lymphocyte expressing chimeric antigen receptor.
