Immune checkpoint inhibitors have been found to have striking activity in a variety of solid malignancies,5–8 including breast cancer, however, they are effective in fraction of patients.9,22–24 Our data suggest that cases lacking PD-L1 might escape immune surveillance by virtue of upregulation of B7-H4 or other non-redundant alternative targets. Here, VTCN1 is linked to breast carcinoma.