CD274 and ovarian cancer: Neutralization of the PD-1 pathway is likely to be the backbone of immunotherapy for treatment of ovarian cancer [21]; however since anti-PD-(L)1 monotherapy of ovarian cancer is inadequate in the clinic [8] and completely ineffective in combination with chemotherapy in preliminary experiments in the ID8-Vegf-Defb29 model (Additional file 1: Figure S1b), we decided to simultaneously target the innate immune system.