Expression of A20 will be determined by extraction of total RNA from whole blood using Trizol and run in standard Northern blot methodology. RNA will by hybridized with [³²P]-dATP labeled A20 probes and glyceraldehyde-3-phosphate dehydrogenase(GAPDH) or β-actin probes to correct for uneven loading. Similar RNA extraction will be performed on liver tissue obtained at time of surgery. Microarray analysis will be performed on the extract to identify specific genes that may be involved in the pathogenesis of HRS.