Moreover, ERAD is an important physiological regulator for cells to orchestrate the steady-state levels of normal protein, including monooxygenase cytochrome p450, cholesterol metabolism regulatory protein HMGCR, INSIG-1 and ApoB; neurodegenerative disease proteins SOD1 and ataxin-3; and the metastasis suppressor KAI1/CD82, phosphatase and tensin homolog (PTEN) and the circadian clock associated Bmal1 [6, 9, 10, 11, 12, 34, 35]. The gene discussed is CYP20A1; the disease is neurodegenerative disease.