Inhibition of GRP75 with MKT-077 at low doses (50–200 nM) induced cell cycle arrest in a panel of human tumor cell lines.25 Furthermore, constant intraperitoneal injection of MKT-077 (3 mg/kg) inhibited tumor growth in a mouse liver cancer xenograft model and potentiated apoptosis of hepatocellular carcinoma cells induced by HSP90 inhibition.51 Both studies suggested a major role for GRP75 in regulating nucleo-cytoplasmic shuttling of the tumor suppressor p53. This evidence concerns the gene TP53 and hepatocellular carcinoma.