In vitro migratory and tubule-forming capacity of CD14⁺/VEGFR-2⁺ and CD14⁺/VEGFR-2^- cells. (A) In a migration assay in the absence and presence of 50 ng/mL concentration of VEGF and 300 ng/mL MCP-1, a significantly higher number of CD14⁺/VEGFR-2⁺ cells (•) than CD14⁺/VEGFR-2^- (○) cells migrated toward VEGF and MCP-1. (B) The CD14⁺/VEGFR-2⁺ cell population produced higher levels of the angiogenic growth factors, VEGF, G-CSF, and GM-CSF than the CD14⁺/VEGFR-2^- population. (C) CD14⁺/VEGFR-2⁺ but not CD14⁺/VEGFR-2^- cells formed capillarylike tubules in Matrigel. HAECs were used as control cells.