SFRP1 and atrial fibrillation: Our analysis confirmed that LLRC17, AK5, SFRP1 and KIAA0101 genes were expressed at higher levels in AF cells in at least two of the three samples (Fig. 2b); while COL11A1, DSC3, COL9A3, and FAM46B were confirmed to be expressed at higher levels in NP cells in at least two of the three samples (Fig. 2c).