Similarly, CRISPR/Cas9- and cytosine base editors were delivered by intravenous in utero injection to establish proof of principle for in utero editing to modify proprotein convertase subtilisin/kexin type 9 (PCSK9) as a target for coronary heart disease and to correct 4-hydroxyphenylpyruvate dioxygenase (Hbd) as therapy for hereditary tyrosinemia type 1 [171]. The gene discussed is PCSK9; the disease is coronary artery disorder.