ASPP2 (amino acid residues 600 –1128) was initially identified as 53BP2 (p53-binding protein 2) in a yeast two hybrid screen using p53 as the bait.

[6] Another yeast two hybrid screening in which Bcl-2 was used as the bait gave rise to the discovery of another fragment of ASPP2 (residues 123-1128) and it was called Bbp.

ASPP2 regulates TP53 by enhancing the DNA binding and transactivation function of TP53 on the promoters of proapoptotic genes in vivo.

[14] The family plays a key role in apoptosis regulation in the intrinsic and extrinsic apoptotic pathways.

[6] Other binding partners have been discovered through the years, indicating the importance of the ankyrin repeats and SH3 domains for protein-protein interactions.

Northern-blot analyses showed that the ASPP2/53BP2 mRNA was expressed in many human tissues such as heart, brain, placenta, lung, liver, skeletal muscle, kidney, pancreas, but at varying levels.

[8] ASPP2 importance in human malignancies is emphasized by studies that show that downregulation of ASPP2 is commonly found in tumors and carcinoma cells expressing wild type p53, and to a lesser extent mutant p53.