Unexpectedly, imaging of animals on day 15 post vaccination (corresponding to the peak T cell response following prime/boost therapy; Additional file 2: Figure S1b) revealed that mice treated with MIS416 Vax + MRB-OVA ± anti-PD-1 (orange and red bars) had increased tumor volume compared to MIS416 Vax (gray bars) and MIS416 Vax + MRB-CONT (blue bars) (Fig. 7c). Here, ROBO4 is linked to neoplasm.