C4-27z and C4opt-27z CAR T lymphocytes secreted low, but reliably detectable levels of Th-2 cytokines, including IL-4 and IL-10, in response to FRα+ cancer cells (Supplemental Figures 3A–3B, 3D–3E) although the response was considerably Th-1 biased. This evidence concerns the gene FOLR1 and cancer.