CYP2E1 and urinary bladder carcinoma: We sequentially omitted 1 study, and calculated the combined ORs of the remaining studies, but the final conclusions were not changed [there were significant associations between CYP2E1 gene polymorphisms and bladder cancer in all genetic models (P < .05)], which suggest that the results were statistically stable and reliable (Fig. 7B, 8B, 9B, 10B, 11B).