Researchers at Nagoya University and Osaka University in Japan have found novel repair pathways of apurinic/apyrimidinic (AP) sites of DNA. Repair of the base excision, which repairs AP sites, is an essential mechanism for cell survival. Its dysfunction causes genome instability disorders, including various cranial nerve diseases. The findings of this study, published in Nucleic Acids Research, should lead to a better understanding of the molecular mechanisms to repair AP sites that are the causes of unexplained and intractable genomic instability diseases.