RAN and hepatocellular carcinoma: Although the Ran-GTP pathway increases microtubule density around chromosomes in mouse oocytes (Schuh and Ellenberg, 2007), neither interfering with Ran-GTP itself in mouse (Dumont et al., 2007; Schuh and Ellenberg, 2007) or Xenopus (Dumont et al., 2007) oocytes nor inhibiting certain Ran effectors such as hepatoma up-regulated protein (Breuer et al., 2010), it prevents meiosis I spindle assembly.