The variant allele frequencies, as calculated from genotypes shown in Table 2, were almost identical for all study groups: CYP3A4*1B was present with allele frequencies of 4.8 (95% CI 2.6–6.9), 3.7 (95% CI 0.8–6.5) and 4.3% (95% CI 2.0–6.6) for liver, stomach and colorectal cancer patients, respectively, and 4.3% (2.1–6.5) for healthy individuals. This evidence concerns the gene CYP3A4 and colorectal cancer.