Members of the glutathione S-transferase (GST) family, such as GST-μ (GSTM1-1) and GST-θ (GSTT1-1), are important candidates for involvement in susceptibility to aflatoxin-related liver cancer because they may regulate an individual's ability to metabolize the ultimate carcinogen of aflatoxins, the exo-epoxide (Johnson et al, 1997). Here, GSTM1 is linked to liver cancer.