Chronic kidney disease (CKD) increases cardiovascular (CV) risk partly through heightened platelet activity, as measured by platelet aggregation to submaximal agonist stimulation.1 However, cost, time, and measurement variability make platelet activity difficult to measure. To address this, we developed the Platelet Reactivity Expression Score (PRESS), which uses transcriptomic data to classify individuals with hyperreactive platelets. Higher PRESS has been shown to be associated with increased CV risk.