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09 October 1987
Vol 238, Issue 4824

About The Cover

Photomicrograph of pancreas from 8½-week-old transgenic mouse carrying an elastase-SV40 gene, stained with Heidenhain's Aniline Blue. A normal islet is adjacent to hypercellular and dysplastic acini, representing a preneoplastic stage associated with expression of SV40 large T antigen in exocrine cells (magnification, about ×800). See page 188. [Albee Messing, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706]