XJTU-L453 is a PI3Kα inhibitor with an IC 50 value of 0.4 nM. XJTU-L453 can inhibit the proliferation of breast cancer cell lines T47D and MCF7, with IC 50 values of 0.2 μM and 0.5 μM, respectively. XJTU-L453 can inhibit the PI3K pathway, induce cell cycle arrest, and trigger cell apoptosis ( apoptosis ). XJTU-L453 also has antitumor activity in MCF7 xenograft mice.