His prior research investigated both the transcriptional regulation of the gene encoding glial fibrillary acidic protein (GFAP), an intermediate filament protein used as a marker for astrocytes, and the biological role of this protein. Initial findings from the transcriptional studies included identification of the GFAP mRNA and protein start sites and analysis of the GFAP basal promoter. Subsequent investigations used site-directed mutation and deletions in GFAP promoter driven mouse transgenes to identify multiple interacting upstream sites affecting transcription, revealing a surprisingly complex regulatory system for this gene.