FD2056 is a potent, orally active PI3K inhibitor, with IC50 values of 0.30, 0.80, 1.10, and 0.42 nM against PI3Kα, PI3Kβ, PI3Kγ, and PI3Kδ, respectively. Additionally, it exhibits inhibitory effects on CDK2-CyclinA2 and CDK4-CyclinD3 with IC50s of 115.95 nM and 2782.15 nM. FD2056 effectively inhibits the proliferation of various breast cancer cell lines, such as MDA-MB-231, MDA-MB-468, and MCF-7, with IC50s of 1.06 μM, 0.04 μM, and 1.40 μM, respectively. The compound also promotes apoptosis in cancerous cells and has been shown to suppress tumor growth [1].