PAH and pulmonary arterial hypertension: Co-expression of a single guide RNA plasmid, a FokI-dCas9-zsGreen1 plasmid, and the presence of a single-stranded oligodeoxynucleotide in PAH_c.1222C>T COS-7 cells – an in vitro model for PKU – corrected the PAH variant and restored PAH activity.