Inserting a large gene precisely and efficiently into a specific DNA location with current CRISPR technology is not yet fully achievable with efficiencies often below 1%.

“to date that ability is still not quite there yet uh we're still working on and many other groups are working on developing Technologies to make that happen uh with high enough efficiency uh we can do it now with very low level maybe less than a perc or maybe just single digit percent uh but for a big Gene that we're trying to put in uh we we don't have a good way to do that yet”