As shown in Fig 4A and 4B, the levels of PI3K and its downstream target pAkt decreased significantly in a concentration-dependent manner exposure to osthole, while the total level of Akt was slightly changed in response to osthole, suggesting that PI3K/Akt signaling plays an important role in osthole mediated cell cycle arrest in gastric cancer cells. This evidence concerns the gene AKT1 and gastric cancer.