APE1/Ref-1: versatility in progress.

Apurinic/apyrimidinic endonuclease1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in base excision DNA repair and in transcriptional regulation of gene expression. Over the past decade and a half, knowledge of the biological functions, interactions, mechanisms of action, and regulation of the protein APE1/Ref-1 has grown exponentially. The multifunctional nature of APE1/Ref-1 is uncovering and has been extensively studied in the cellular response against oxidative stress. Recent evidence shows a biological role of APE1/Ref-1 can be modulated by the different post-translational modification. Because of APE1/Ref-1 importance to genomic stability and cell survival, APE1/Ref-1 is focused as the leading therapeutic target molecule for the oxidative stress condition or pathologic conditions such as cancer. This forum, dedicated to APE1/Ref-1, provides ample testimony that even though we have learned a great deal about APE1/Ref-1 over the past 15-plus years, our knowledge still constitutes the tip of the iceberg when it comes to understanding this versatile protein.