Would you drink fluorescent green wine? Most molecular biologists-in-training experience their first taste of genetic engineering by transferring a jellyfish gene into (harmless) Escherichia coli, making the bacteria glow green under UV light. One slow day this past winter, my lab-mates and I contemplated the ramifications of transferring that same gene into Vitis vinifera. Fluorescent green wine? Fluorescent green wine! Oh, wait a minute. Do we seriously want such a thing? And has someone already done it?