The p53 tumor suppressor is a transcription factor that controls the expression of many genes implicated in cell growth control, DNA repair, cell-cycle arrest, apoptosis, angiogenesis, redox regulation, metastasis, nitric oxide production and protein degradation. p53 transactivation is regulated by phosphorylation and interaction with an inhibitory protein, MDM2. Mutational inactivation of the p53 gene product is one of the most common genetic events that occur in human cancers. TransAM p53 contains an antibody specific for the active form of p53 when it is bound to the target DNA.


