TP53 and hepatocellular carcinoma: To further delineate the function of p53 in the regulation of the MCP-1 gene, we used the p53 negative hepatocellular carcinoma cell line Hep3B, stably co-transfected with an expression plasmid encoding a murine temperature-sensitive mutant of p53 (p53val135) and a vector for puromycin resistance ("4Bv") or with the resistance marker alone ("BT2E").