The results demonstrated that FGF2 could increase FGFR2+ CAF progenitors in BM and FGFR2+ fibrocytes in peripheral circulation in a dose-dependent manner, while blocking FGF2 led to a marked reduce of FGFR2+ CAFs in tumor, suggesting that FGF2 is responsible for the mobilization and expansion of CAF progenitors. The gene discussed is FGF2; the disease is neoplasm.