PI3K/HDAC-IN-4 (Compound 31f) is a dual inhibitor targeting PI3K and HDAC, with an IC50 of 0.2μM. It demonstrates high selectivity for HDAC1-3, with IC50 values of 75.5 nM, 70.9 nM, and 1.9 nM, respectively. As a potent pan-PI3K inhibitor, PI3K/HDAC-IN-4 has IC50 values of 2.5 nM, 80.5 nM, 10.0 nM, and 57.2 nM for PI3Kα, β, δ, and γ, respectively. This compound effectively induces apoptosis in tumor cells by concurrently inhibiting the PI3K/AKT/mTOR signaling pathway and HDAC1-3. It shows significant antiproliferative activity across various tumor cell lines, such as MV4-11, Jeko-1, HL60, and MCF-7, with IC50 values of 0.2, 0.9, 0.8, and 1.5 μM, respectively. PI3K/HDAC-IN-4 is applicable in the study of lymphoma and leukemia.