BOSTON – A group of U.S. senators, including Elizabeth Warren and Ed Markey of Massachusetts, is still seeking answers on federal barriers to research on medical marijuana and hit U.S. agencies for a lack of coordination with states on the issue. Warren, Markey and six other senators sent a letter in July asking for information on federal agencies' efforts on medical marijuana research.

BOSTON – A group of U.S. senators, including Elizabeth Warren and Ed Markey of Massachusetts, is still seeking answers on federal barriers to research on medical marijuana and hit U.S. agencies for a lack of coordination with states on the issue. Warren, Markey and six other senators sent a letter in July asking for information on federal agencies' efforts on medical marijuana research.