Similarly, the high levels of secreted IL-2 and IFN-γ, two prominent serum markers for CRS, by the condCAR T cells (82.5 ng/ml IL-2, 253.8 ng/ml IFN-γ) were comparable to those of the conventional CAR T cells (89.7 ng/ml IL-2, 242.6 ng/ml IFN-γ) in the absence of MTX, but were dramatically reduced in the presence of 100 μM MTX (0.1 ng/ml IL-2, 1.6 ng/ml IFN-γ) and to levels comparable to non-transduced T cells (NTD; 0.1 ng/ml IL-2, 0.6 ng/ml IFN-γ; Fig. 3d). This evidence concerns the gene IL2 and congenital rubella syndrome.