The diagnostic problems of BC (at present, the main diagnostic and prognostic tool is cystoscopy), as well as the role of environmental exposure (about 50% of BC patients are smokers and smoking is considered as the primary cause of BC development) and genetic predisposition (genotype of N-acetyl-transferase NAT2 and glutathione transferase GST), have motivated us to look for BC markers which combine the risk factors mentioned above and are less invasive than cystoscopy with biopsy. Here, NAT2 is linked to breast cancer.