VWF stimulates HUVEC adhesiveness for hMSCs. (a) Shows changes in HUVEC adhesiveness for hMSCs caused by treatment with 4 μg/ml vWF (black circle) or HBSS (white circle) for 0 to 9 hours. Asterisks mark time points where adhesion of hMSCs to HUVECs treated with vWF was different (t-test, P-value <0.05) from the adhesion to HUVECs maintained in HBSS. (b) Shows the dose-response curve of HUVEC adhesiveness for hMSCs after treatment of HUVECs with 0 to 6 μg/ml vWF for four hours. Data are shown as mean ± SD of eight independent measurements.