CD28 and ovarian cancer: anti-αFR.CD3ζ, anti-αFR.CD28.CD3ζ and anti-αFR.CD28.4-1BB.CD3ζ, the latter presented the highest cytotoxicity, reflected in stronger degranulation and cytokine secretion, greater proliferation and longer persistence when incubated with αFR-expressing ovarian cancer cells.