WT1 and myocardial infarction: To determine whether BNP stimulates WT1+ cell proliferation and/or WT1 re-expression in endothelial cells, the percentage of proliferating WT1+ cells (number of WT1+ BrdU+ cells relative to the total number of WT1+ cells) was assessed 3 and 10 days after MI in hearts from BNP-treated or untreated mice.