Fig. 2

Gating strategy for the identification of circulating collagen I+ cells, i.e. fibrocytes. Debris, B cells, monocytes and dead cells were removed by an electronic gate as described in the legend to Fig. 1. Circulating fibrocytes were identified as CD34+, CD45+ and collagen I+. The expression of CXCR4 was then evaluated among circulating fibrocytes. Lower panels, referred to cultured human fibroblasts, represents a positive control of collagen I staining (>95 % cells were positive). FSC forward scatter, SSC side scatter