Studies have revealed that GSTM3 obviously affects the susceptibility of individuals to cancer, such as esophageal cancer, hepatocellular carcinoma, colorectal cancer, urinary bladder cancer, breast cancer, and prostate cancer (Loktionov et al., 2001; Mitrunen et al., 2001; Jain et al., 2007; White et al., 2008; Kesarwani et al., 2009; Mitra et al., 2009). The gene discussed is GSTM3; the disease is colorectal cancer.