There was something potentially related in the news the other day…
https://www.rt.com/news/520687-new-crisproff-method-reversible/
CRISPR-on, CRISPR-off: New game-changing gene editing technique is entirely reversible
US researchers have unveiled a significant upgrade to the CRISPR gene editing system, which, unlike its predecessor, can target specific genes with high precision and make completely reversible changes.
The new gene editing technology, developed by Whitehead Institute Member Jonathan Weissman and University of California San Francisco assistant professor Luke Gilbert, is called CRISPRoff.
It is capable of controlling a gene with laser-like precision, while leaving the broader strand of DNA unchanged. Furthermore, the edits are not only stable enough to be inherited through hundreds of cell divisions but are also fully reversible.
“We can do this for multiple genes at the same time without any DNA damage, with a great deal of homogeneity, and in a way that can be reversed. It’s a great tool for controlling gene expression,” Weissman says.
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They compared the deliverability potential of CRISPRoff into a human being to the newly-developed RNA technology which forms the basis of both the Moderna and BioNTech coronavirus vaccines, but their gene-editing technique will have to undergo far more rigorous testing before it can even begin clinical trials in human hosts.