CDKN1B and hepatocellular carcinoma: The role of FOXM1 in the early stages of tumorigenesis became clearer with the observation that hepatic FOXM1b expression in transgenic mice promotes cell proliferation in pre-neoplastic and early neoplastic lesions, and has a less clear effect on hepatocellular carcinoma development [38], as FOXM1 deficiency increases nuclear p27/Kip1 in normal hepatocytes.