This Nox1 overexpression is also observed in different prostate cancer cell lines (PC3, DU145, LNCaP) compared to normal cells, resulting in an increase in ROS (e.g., O2-• and H2O2), indicating that the NAD(P)H oxidase (Nox) system is involved in the extra-mitochondrial generation of ROS and plays a key role in the development of the malignant phenotype in prostate cancer cells (Kumar et al. 2008; Luo et al. 2009). Here, FMO5 is linked to prostate cancer.