604 T HCCs from Western countries. The population of

Qidong is exposed to high levels of aflatoxin B1(AFB), a fungal toxin that has been shown to induce the same mutation in cultured human HCC cells. To investigate the role of AFB1 and of these p53 mutations in hepatocarcinogenesis, normal liver samples from the United States, Thailand and Qidong (where AFB1 exposures are negligible, low and high, respectively) were examined for p53 mutations. The frequency of the AGG to AGT mutation at codon 249 paralleled the level of AFB1 exposure, which supports the hypothesis that this toxin has a causative-and probably early-role in hepatocarcinogenesis. Comment This paper follows on from previous data correlat