Newly abundant genomic data is driving formation of all sorts of technology-based businesses. But markets for new tools are already chaotic and competitive, in part because customers know they've got many choices. Nanogen is in the thick of it. Pharmaceutical researchers weren't so interested in the firm's low-density gene chips, so the firm is now focusing on the clinical diagnostics market where managers believe flexible, accurate NanoChips will be better appreciated. The trouble is, the long-foretold market for molecular diagnostics still barely exists. On one hand, market immaturity spells opportunity for Nanogen as an early entrant, but it also means the company has to bushwhack a new path for its technology. It's not easy. For now, Nanogen is marketing its system to researchers in clinical diagnostic labs, university hospitals and government institutions-scientists at the cutting edge, who may become key content developers. The firm is also working to better serve drug makers. The company's customers display little loyalty yet: they're eager to try other new technologies too. Nanogen is betting that the superiority of its system will win hearts and minds as the market for molecular diagnostics takes shape.