CYP7B1 and neurodegenerative disease: In 2019, another group used LNPs to deliver CYP7B1 mRNA as a treatment for hereditary spastic paraplegia type 5 (SPG5), a neurodegenerative disease caused by CYP7B1 gene loss-of-function mutations, and this resulted in noteworthy oxysterol degradation in liver and serum after two days of treatment, as well as the restoration of functional human CYP7B1 protein and the elimination of abnormal cholesterol metabolites [255].