GPD2 and neoplasm: Treatment of DHA on GPD2 KO cells activated Akt and its downstream signaling pathway components, including mTOR and p70 S6K, as evidenced by the increase in the phosphorylated form of these proteins (Figure 5D). In connection with the Akt signaling, we also measured the changes in cell cycle status in GPD2 KO cells, and the KO cells exhibited cell cycle arrest at S phase (Figure S5). To see the in vivo relevance of the proposed GPD2-ether lipid-Akt axis, we measured the ether lipid level in the grafted tumor tissues by using LC-MS.