FGFR2+ fibrocytes were isolated from either ESCC patients or KYSE30 tumor-bearing mice (cell purity > 94%; Fig. S1), transfected with lentiviral vector carrying Luciferase gene and injected into the tail vein of KYSE30 (labeled with GFP) tumor-bearing mice. This evidence concerns the gene FGFR2 and esophageal squamous cell carcinoma.