ROBO2 and pulmonary emphysema: In contrast, LASSO-selected proteins previously implicated in emphysema, namely adiponectin, IL1RN, S100-A12, sRAGE, and ROBO2, showed smaller relative coefficients (except for ROBO2 and adiponectin) and added less unique variance in percent emphysema, suggesting overlap with other clinical predictors of percent emphysema or lower independent effects.