However, only transfer of human T cells expressing the costimulated MOv19-BBζ CAR mediated tumor regression in immunodeficient mice bearing large, established FRα-positive human ovarian cancers, while MOv19-ζ CAR-T cells were ineffective, recapitulating previous clinical results with FRα CAR T cells lacking costimulatory signals. Here, FOLR1 is linked to ovarian cancer.