CDKL5 and sickle cell disease: We next evaluated editing with PE7 at additional genomic targets5,18, including ones associated with sickle cell disease (HBB), prion disease (PRNP), familial hypercholesterolaemia (PCSK9), adoptive T cell transfer therapy (IL2RB), HIV infection (CXCR4) and CDKL5 deficiency disorder (CDKL5) (Fig. 5a,b).