Flow cytometry revealed that the proportions of MDSCs were significantly reduced in the spleen, tumor, and blood of GPR84−/− tumor-bearing mice compared to the wild-type (WT) group (Fig. 2a, b), whereas CD8+ T cells were remarkably increased (Fig. 2c, d) in GPR84−/− tumor-bearing group. Here, GPR84 is linked to neoplasm.