Overexpression of FCN3 induced apoptosis and inhibited cell proliferation. (A) FCN3 mRNA and protein level in HCC cells and normal liver cell L02. (B) KEGG pathway analysis of all DEGs in cell transcriptome sequencing and the p53 signaling pathway shown by the black dotted frame. (C) Single-gene GSEA analysis of FCN3 with the TCGA data. (D) FCN3 overexpression in HCCLM3 and SK-Hep1 increased apoptosis whereas FCN3 knockdown decreased apoptosis of HepG2 cells. (E) FCN3 overexpression inhibited cell proliferation in HCCLM3 and SK-Hep1, silenced FCN3 promoted cell proliferation in HepG2. (F) Representative images of EdU positive cells from an EdU incorporation assay. (G) Western blot analysis showing expression of FCN3, p53, Bax, Bcl2, and Cleaved caspase3 in HCCLM3 and SK-Hep1 transfected with FCN3 and HepG2 transfected with siFCN3. (H) Apoptosis rate of HCCLM3 cells overexpression FCN3 and treated with Pifithrin-α (p53 inhibitor, 30uM, 24h) as determined by flow cytometry. Results are expressed as the mean±SD of three independent experiments. **P<0.01, ***P<0.001.