Cover photograph (Copyright © 2007, American Society for Microbiology. All Rights Reserved.): Whole-mount {beta}-galactosidase staining at embryonic day 12.5. Inspection of mouse embryos shows that receptor protein tyrosine phosphatase {gamma} (RPTP{gamma}) is expressed in a variety of tissues during embryogenesis. RPTP{gamma} is expressed in both embryonic and adult brains. Specifically, we detected RPTP{gamma} expression in cortical layers II and V and in the stratum pyramidale of the hippocampus, indicating that RPTP{gamma} is a marker for pyramidal neurons. (See related article in July 2006, vol. 26: issue 13, p. 5106..)