Treatment of cancer cells with anti-CD3 × anti-tumour antigen and anti-CD28 × anti-tumour antigen cross-interacting bispecific antibodies led to enhanced tumour cell-dependent T-cell activation in vitro.53 Moreover, anti-CD28 × anti-PSMA and anti-CD28 × anti-mucin 16 (MUC16) bispecific antibodies were shown to potentiate in vivo anti-tumour activity of CD3+ bispecific T-cell redirectors in humanised immunocompetent mouse models of prostate and ovarian cancer, respectively.54 Importantly, combination therapy did not elicit toxicity in cynomolgus monkeys in vivo. The gene discussed is MUC16; the disease is cancer.