If biomarkers can help isolate treatment responses from only one patient subgroup, even that can help improve the odds of success at clinical trials. And, well, that's certainly better than nothing. That's essentially what Roy H. Perlis says in an editorial appearing in the American Journal of Psychiatry. Pointing to a couple of subgroup-specific results appearing in this month's issue, Perlis says that the idea of simultaneous validation of a new treatment, plus new tests involving biomarkers to guide how the treatments are used, are at last becoming a subject of interest in the pharma world. "After some resistance to the notion of reducing their potential market share by looking for more responsive subgroups, drug developers have come around to the notion that a smaller piece of a big pie is better than no pie at all," Perlis writes. Editorial