Chinese researchers led by Professor Gao Caixia have achieved a breakthrough in genome editing by developing Programmable Chromosome Engineering (PCE) systems that enable megabase-scale precise DNA manipulations in eukaryotic cells. Combining novel asymmetric Lox site variants, AI-informed protein engineering of Cre recombinase, and scarless editing strategies, they enhance recombination efficiency and accuracy. This advance promises transformative impacts for plant and animal genetics, opening avenues for complex genomic rearrangements and precise engineering at unprecedented scales.