However, only a few of the studies analyzed clinical material from patients affected by bladder cancer, confirming a positive correlation of HO-1 level with the proliferation of cancer cells, VEGF-induced angiogenesis, and, finally, the malignant behavior of the cancer [24,27,28,29], whereas none of them involved comparison to the healthy tissue. This evidence concerns the gene HMOX1 and urinary bladder carcinoma.