Lenvatinib induced apoptosis and regulated cell cycle arrest progression in GBC-SD and NOZ cells. GBC-SD and NOZ cells were treated with 25 or 50 µM lenvatinib for 48 h, stained with Annexin V-FITC and PI, and analyzed by flow cytometry. (A) Quantification of apoptotic rate. (B) Distribution of cell cycle. (C and D) Protein expression of caspase-9, CytoC, Bax, CDK2, CDK4 and cyclin D1 were detected by western blotting. β-actin or GAPDH was used as a loading control. *P<0.05 vs. NC. Len, Lenvatinib; FITC, fluorescein isothiocyanate; CytoC, cytochrome c; Bax, Bcl-2-associated X protein; NC, negative control.