The tumor‐tropic activities of MSC, which could be inhibited by targeted silencing of IGF‐2 in tumor cells, could be fully rescued by the addition of rIGF‐2 (Fig. 1C), suggesting that IGF‐2 is critical for tumor tropism of MSCs, which concurs with the findings of Fiedler and colleagues 10. This evidence concerns the gene IGF2 and neoplasm.