Serotonin had no effect on the subcellular localization of FOXO3a in serum-deprived HCC cells .However, serotonin increased the phosphorylation of AKT and FOXO3a in serum-deprived Huh7 cells, but not in HepG2 or Hep3B cells. The gene discussed is FOXO3; the disease is hepatocellular carcinoma.