Studies have demonstrated that glutamine metabolism can regulate tumor growth and survival by influencing AMPK signaling, the PI3K/AKT pathway, and the STAT1 signaling pathway.211 In particular, under stress conditions such as glucose deficiency, cancer cells maintain survival by increasing glutamine metabolism-related enzyme and transporter expression.212 Furthermore, glutamine metabolism is closely connected with cell cycle regulation. Here, PIK3CA is linked to cancer.