Recent models suggest that hepatocellular carcinoma (HCC) develops through several independent pathways marked by key mutations in the beta-catenin or p53 gene. An additional pathway potentially is marked by aberrant expression of a-fetoprotein (AFP). To see whether these potential markers are expressed independently, we immunostained sequential sections from 55 HCCs. Of the cases, 30 (55%) were positive for 1 or more proteins: AFP, 19 cases (35%); p53, 12 cases (22%); and beta-catenin, 9 cases (16%). Seven tumors (13%) were positive for more than 1 protein, with 4 of 7 positive in the same area of tumor and 3 of 7 positive in different areas of the carcinomas. By statistical analysis, expression of the markers was independent of one another and of tumor size. Concurrent evaluation of p53, beta-catenin, and AFP protein expression showed no associations, supporting models in which these proteins might serve as markers of independent pathways in the development of HCC.