Cell Signaling Technology Announces Continuation of Collaboration with AstraZeneca to Provide CST's PhosphoScan® Platform for Kinase Inhibitor Proteomic Profiling

Business Wire, April 12, 2006

DANVERS, Mass. -- Cell Signaling Technology, Inc. (CST) announced today a third agreement with AstraZeneca under which it will continue to perform CST's PhosphoScan(R) technology to identify phosphorylation profiles and prospective biomarkers of kinase targeted lead compounds. CST's PhosphoScan(R) proteomics technology is a patent-pending strategy that enables the discovery of drug target phospho-profiles (Phospho-Signatures(TM)) in cells and disease tissues. The PhosphoScan(R) technology involves immunoaffinity purification and mass spectroscopy and was described in the journal Nature Biotechnology (Rush J. et al, Nat. Biotechnol. 23, 94-101 (2005)). The Phospho-Signatures(TM) discovered using PhosphoScan(R) may enable biomarker assays for target validation and therapeutic kinase inhibitor clinical development.

"Our on-going relationship with AstraZeneca has enabled to CST apply its phosphoproteomics capabilities to deliver valuable information supporting AstraZeneca's kinase inhibitor programs," said Christopher Bunker, CST's Director of Business Development. "PhosphoScan(R) has provided value to our partners as well as to CST's internal cancer research programs, particularly in understanding tyrosine kinase activation and inhibitor mechanism of action. CST has in addition recently implemented methods for serine/threonine kinase PhosphoScan(R) profiling, as well as quantification strategies, which further enhance CST's ability to focus on the most relevant biomarkers of kinase target activation and inhibition. AstraZeneca can also benefit, under our agreement, from CST's expertise in antibody and immunoassay development for biomarkers discovered using PhosphoScan(R)."

About Cell Signaling Technology

Cell Signaling Technology is the market leader in the development and commercialization of phospho-specific antibodies and assays for kinase and pathway analysis. CST's phospho-specific antibodies are validated in multiple assay platforms and are critical reagents in all stages of pharmaceutical drug discovery and development. PhosphoScan(R) leverages CST's core capabilities in antibody development to deliver unparalleled insight into cellular phosphorylation profiles enabling more efficient and informative kinase drug discovery and clinical development. CST is commercializing the PhosphoScan(R) technology through research alliances and licensing opportunities. More information can be obtained at the Company's website www.cellsignal.com