The DNA base editors, developed at Harvard University under David Liu, allow altering the genomic structure of DNA. The base editors include BE3, BE4 and ABE7.
BE3 and its later version, BE4 allow to change the nucleobase C to T and nucleobase G to A. ABE7 allows to change A-T base pairs into G-C base pairs. The system works by rearranging the atoms in the target base pair and then tricking cells into fixing the other DNA strand to make the change permanent.