In 2017, Biomarin received FDA approval for tripeptidyl peptidase 1 (cerliponase alfa) as a treatment for the underlying cause of Batten disease, the deficiency of tripeptidyl peptidase (TPP1) a lysosomal enzyme (U.S. Food Drug Administration, 2017). The gene discussed is TPP1; the disease is juvenile neuronal ceroid lipofuscinosis.