Meanwhile, the growth of the residual tumor cells as represented by Ki67 staining was also significantly suppressed in the MnP@DOP-Gel + aPD1 group, compared to other groups (Figure 4L, Figure S20), indicating the synergistic inhibition of tumor cell proliferation of MnP@DOP-Gel and free aPD1. This evidence concerns the gene MKI67 and neoplasm.