AKT1 and lymphoma: 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.