To explore the involvement of BMP1.3 in cardiac fibrosis, we exploited our in house-developed ELISA (validation in Supplementary methods) to quantify BMP1.3 levels in the plasma of either healthy individuals or patients who experienced a recent MI, as diagnosed by ST-elevation at electrocardiography and increased troponin T concentration. The gene discussed is GDF6; the disease is myocardial infarction.