For the overall data containing 2164 cases and 4160 controls, significant associations of CYP1A1 Ile462Val polymorphism with acute leukemia risk were shown under the homozygote comparison (OR = 1.49; 95%CI = 1.11–1.98), the dominant (OR = 1.26; 95%CI = 1.05–1.51) (Figure 2) and the recessive (OR = 1.38; 95%CI = 1.04–1.83; P = 0.247 for heterogeneity) models, indicating that individuals carrying the variant Val allele may have an increased acute leukemia risk compared with those bearing the wild-type Ile allele. This evidence concerns the gene CYP1A1 and acute leukemia.