A Genetic Risk Factor for ALS (IMAGE) University of Pennsylvania Caption A role for the polyQ protein ataxin 2 in ALS was identified using yeast (top left), fruit fly models (top middle), human ALS motor neurons (top right) and genetic analysis in ALS patients (above). Credit University of Pennsylvania Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.