CasNano

CasNano is an ultracompact engineered CRISPR-associated (Cas) protein developed by Epitor Therapeutics. Comprising fewer than 400 amino acids, it is designed as a highly compact genome-editing tool that can be efficiently packaged into adeno-associated virus (AAV) vectors, overcoming the size limitations of traditional Cas proteins such as spCas9. CasNano enables targeted gene editing and epigenetic modulation—including demethylation, methylation, and gene activation or repression—by fusing with various protein effectors. It supports multiplexed editing and demonstrates over a 20-fold improvement in targeting efficiency due to directed evolution and re-engineering of its guide RNA components. Its small size allows co-packaging with large effectors like TET demethylases for precise epigenetic editing within a single AAV vector[2][4].