Richmond, California December 31, 2001 Sangamo BioSciences, Inc. (Nasdaq: SGMO) today announced the publication of results using its engineered zinc finger DNA-binding proteins (ZFPs) to repress expression of a gene required for the development of fat cells (adipogenesis). The paper is being published in the January 1, 2002 issue of the journal Genes & Development and is co-authored by scientists from Pfizer Inc (NYSE: PFE) and Sangamo.

The data presented in the paper represent a significant advance in the external application and validation of Sangamos ZFP transcription factor (ZFP-TF) technology, which enables the specific control of genes within an organism. Sangamo ZFP-TFs specifically repressed expression of a gene variant, or isoform, in a mouse cell type that is the precursor to fat cells. Repression of the gene prevented the cells from developing into mature fat cells (adipocytes).

This initial finding led the scientists to further study the role of the gene, known as PPARgamma, in the development of fat cells. In particular, through the use of two ZFP-TFs that bind at slightly different positions on the gene, the scientists for the first time precisely identified the PPARgamma2 isoform as the gene variant critical for fat cell development.

In a commentary published in the same issue of Genes & Development, Mitchell A. Lazar, M.D., Ph.D., Professor of Medicine and Genetics, Chief, Division of Endocrinology, Diabetes and Metabolism and Director, Penn Diabetes Center of the University of Pennsylvania School of Medicine, said, ". . . [T]he relative importance of the two PPARgamma isoforms for adipogenesis has remained an open question because PPARgamma1 and PPARgamma2 are expressed at comparable levels in adipocytes. Ren and coworkers have elegantly addressed this question." Dr. De
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Contact: Carol DeGuzman
cdeguzman@sangamo.com
510-970-6000 x256
Eukarion, Inc
31-Dec-2001