Using a combination of multisite λ−dynamics(MSλD)together with in vitro IC50 assays, weevaluated the polypharmacological potential of a scaffold currentlyin clinical trials for inhibition of human neutrophil elastase (HNE),targeting cardiopulmonary disease, for efficacious inhibition of Proteinase3 (PR3), a related neutrophil serine proteinase. The gene discussed is PRTN3; the disease is cor pulmonale.