Mutation in DJ1 (Daisuke-Junko-1), Parkin, Pink1 (acid protein phosphatase and tensin homolog (PTEN)-induced kinase 1), and ATP13A2 (ATPase type 13A2) is responsible for monogenic PD forms, and other genes, including MAPT (microtubule-associated protein tau), GBA (glucocerebrosidase,), APOE (apolipoprotein E), have been associated with an increased risk of developing PD. The gene discussed is APOE; the disease is Parkinson disease.