MRC1 and neoplasm: Further, immunostaining of tumors from 4T1 tumor-bearing mice treated with PU-WS13 showed a significant decrease in the percentage of CD206+ cells compared with untreated mice in correlation with in vivo imaging findings (0.82 ± 0.31 %ID/g vs. 2.16 ± 0.44 %ID/g of nucleated cells in the tumor, p = 0.0056) (Figure 3C).