Umbralisib (TGR-1202) sulfate, an orally active compound, serves as a potent, selective inhibitor targeting both PI3Kδ and casein kinase-1-ε (CK1ε), with EC50 values of 22.2 nM and 6.0 μM, respectively. It demonstrates unique immunomodulatory effects on T cells in chronic lymphocytic leukemia (CLL) and is applicable in the research of hematological malignancies.