Nevertheless, controversial studies exist when it comes to the effect of heme degradation by HO1 in cancer cells—some found that HO1 deficiency led to defective DNA, carcinogenesis, and resistance to ferroptosis (discussed hereafter); other data, however, indicated that HO1 induction promotes cancer cells antioxidant potential and cancer growth [217,218]. This evidence concerns the gene HMOX1 and cancer.