EPOR and cholesteryl ester measurement: In lieu of coupling the tEPOR cDNA and therapeutic edit at the same locus, an alternative strategy would be to multiplex two editing events at different loci to simultaneously truncate the endogenous EPOR and introduce the original β-thalassaemia correction vector at HBA1. This strategy may have the additional advantage that the endogenous EPOR truncation will more reliably recapitulate CE.