Alterations in catalase expression are responsible for various diseases, such as neurological disorders (Alzheimer’s disease, Parkinson’s disease), psychiatric disorders (bipolar disorder, schizophrenia), cardiovascular diseases (hypertension), metabolic diseases (diabetes mellitus, autoimmune diseases (vitiligo)), Wilson’s disease, and cancer (Fig. 3) (Glorieux and Calderon 2017). This evidence concerns the gene CAT and Alzheimer disease.