The SwR-CAR T cell activity was assessed against a panel of STEAP1+/− prostate cancer cell lines with or without over-expression of TGFβ, or with added TGFβ, by use of flow cytometry cytokine and killing assays, Luminex cytokine profiling, cell counts, and flow cytometry phenotyping. This evidence concerns the gene TGFB1 and prostate cancer.