TNF and congenital rubella syndrome: In contrast to CD19-CAR-T cells, the amount of CRS-associated cytokines IL-6, TNF-α and IFN-γ of iKP-19-CAR-T cells was decreased notably during lysing Daudi cells in vitro and this phenomenon was also observed in vivo, which indicated that iKP-19-CAR-T cells were safer than CD19-CAR-T cells.