...-occurring Acr (Anti-CRISPR) proteins can help control CRISPR activity. Acr proteins have evolved in phages...LmoCas9 and SpCas9. Acr proteins can be used to control both when and where genome editing happens. CASANOVA...Dominik Niopek’s lab , is a way to optogenetically control genome editing by fusing the anti-CRISPR protein...photosensitive LOV2 domain . Several labs have also controlled Acr activity with endogenous cell-type specific...have also been used in in vivo RNA imaging or to control alternative splicing. Figure 13: Overview of RNA...Engineered anti-CRISPR proteins for optogenetic control of CRISPR–Cas9. Nature Methods , 15 (11), 924–927...homology-directed human genome engineering by controlled timing of CRISPR/Cas9 delivery. eLife . 3 e04766...