PTPRC and atrial fibrillation: We observed that fresh AFSCs can be reliably isolated from mouse AF and have equal CD45 expression to mouse FL-derived HSC and BM HSC while differing from FL-HSC for Sca-1 expression and from BM-HSC for cKit and Sca-1 (Fig. 1A and Supplementary Fig. S2 for co-expression of stem cell markers).