To evaluate the effect of dual targeting UBR5 and PD-L1 on the spontaneous lung metastasis of 4T1 tumors, 5×105 tumor cells were administrated i.v. to mice and lung metastasis was measured at Day 12 post injection using the 6-thioguanine clonogenicity assay (Figure 3D). Here, CD274 is linked to neoplasm.