Since HO-1 overexpression promotes chemoresistance of cancer cells, tumors in which the HO-1 L allele of the (GT)n locus has been detected (e.g., malignant mesothelioma, lung carcinoma, and digestive tract cancers) may have a better therapeutic response towards some antiblastic drugs, such as daunorubicin, gemcitabine, and cisplatin [183,217,218,219]. This evidence concerns the gene HMOX1 and cancer.