hMSCs modify the SC tumour vessel structure. (A) Images of vessels in TSA-pGL3 tumours in xenograft tumour models with and without injection (SC or IV) of hMSCs after staining with haematoxylin and a CD31 antibody (100× magnification). Scale bar = 200 μm. (B and C) Quantitative analyses of vessel density (B) and vessel length (C) The results are expressed as the mean ± SD. (n = 5 mice; six images/mouse; *P <0.05, **P = 0.0016, ***P <0.0001). (D) Box plots of αSMA+ cells in tumour. The results are expressed as the mean ± SD (n = 2 to 9 photographs/tumour; two to five mice/group; ***P <0.0001). hMSC, human mesenchymal stem cell; IV, intravenous; SC, subcutaneous; SD, standard deviation.