p53 plays a crucial role in maintaining ordered proliferation, growth, and differentiation of normal cells. While p53 normally exists in the cell at a very low level and in a relatively inactive form, in response to cellular stress it accumulates in the nucleus, where it binds to specific DNA sequences. p53 is known to induce or inhibit the expression of more than 100 target genes. Mutations of the p53 gene is the most frequently encountered genetic event in cancer, thereby inactivating p53 and resulting in the disruption of the expression of target genes. Therefore, expression profiling of p53 target genes will facilitate the functional study of p53. 
Signosis has developed a plate-based array for profiling 20+ p53-regulated genes. By using this assay, researchers are able to compare gene expression in up to three samples on a single microtiter plate.