Investigating a CD3xHER2 BiTE, Juntilla et al. found that PD-L1 expression inhibits antitumour activity by redirected T-cells in vitro, and this translated to an 82% rate of complete response to the CD3xHER2 BiTE in combination with anti-PD-L1 mAb in HER2+ mouse tumours compared to 43% of mice achieving a >80% reduction in tumour mass with CD3xHER2 BiTE monotherapy [17]. The gene discussed is ERBB2; the disease is neoplasm.