In addition, although it has previously been reported that human MSCs suppress tumor development by inhibiting target-cell Akt activity (6), we did not find that Akt inactivation affected the proliferation of the A20 cells co-cultured with MSCs (Fig. 1C), suggesting that the inhibition of lymphoma cell proliferation by mouse MSCs may not involve the inhibition of Akt. This evidence concerns the gene AKT1 and neoplasm.