SPIC and atrial fibrillation: Cells isolated from the liver on post injury day seven were assessed by flow cytometry using standard markers and autofluorescence (AF) to quantify Kupffer cells (F4/80++, CD11b+, AF high, Spi-C+) and monocytes (F4/80+, CD11b++, FSC/SSC low, AF low) as Spi-C positive or Spi-C negative (Fig. 6A).