**2.4 Microarray analysis of gene expression**

RNA was purified from 20-70 mg liver or liver tumor tissue fixed in RNAlater using an RNeasy MIDI kit (Qiagen, Valencia, CA) as directed, except 50% ethanol, rather than 70% ethanol, was added to the homogenized lysate. Fluorescently labeled cDNAs were generated using Agilent Quick-Amp Labeling kits and hybridized in competition with a mixed-sex, whole-tissue liver cDNA control to Agilent Whole Mouse Genome arrays (Item #G4122F, Agilent, Santa Clara, CA). Arrays were scanned using an Agilent DNA Microarray Scanner G2505C.
