Clinically, CST3 has been extensively studied for its roles in neurodegenerative disorders.18 Abnormal accumulation or mutations of CST3 have been found to be associated with Alzheimer’s disease due to its ability to inhibit proteases involved in amyloid-β protein degradation, thus impacting amyloid plaque accumulation in the brain. The gene discussed is CST3; the disease is early-onset autosomal dominant Alzheimer disease.